近年来, 随着种群生态学的发展, 种群生物模型(尤其是捕食-食饵模型)引起了国内外学者的极大关注.文献[1]讨论了一类具有修正的Leslie-Gower与Holling Ⅱ反应函数的不带交叉扩散的捕食-食饵模型解的有界性和全局渐近稳定性; 文献[2]利用锥上不动点理论和线性稳定性理论研究了一类具有Holling Ⅲ型捕食-食饵模型平衡态正解的存在性与稳定性; 文献[3]利用极值原理和分歧理论研究了一类在Dirichlet边界条件下带有广义Holling Ⅲ型功能反应项的修正型Leslie捕食食饵模型的平衡态正解的局部分歧以及全局分歧.但以上研究都没有考虑到种群间的交叉扩散的影响.事实上, 在某些生态系统中, 种群间的相互影响在种群扩散中也起着非常重要的作用[4-14].据此研究具有Leslie-Gower与Holling Ⅱ反应函数的带有交叉扩散的捕食-食饵模型将尤为重要.对于无交叉扩散的情形, 文献[15-16]主要讨论了其正解的存在性, 唯一性, 稳定性以及其脉冲效应.本文在文献[15-16]的基础上考察如下带有交叉扩散和修正的Leslie-Gower与Holling Ⅱ反应项的捕食-食饵模型
$ \left\{ \begin{array}{l} - \Delta \left[ {\left( {1 + av} \right)u} \right] = u\left( {a - u - cv/\left( {{k_1} + u} \right)} \right),\;\;\;\;\;x \in \mathit{\Omega ,}\\ - \Delta \left[ {\left( {1 + \beta u} \right)v} \right] = v\left( {b - bv/\left( {{k_2} + u} \right)} \right),\;\;\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ u = v = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (1) |
其中Δ为Laplace算子, Ω为Rn中具有光滑边界的有界开区域, u, v分别为食饵和捕食者的浓度, a, m, k1, b, c, k2都是正常数, α和β分别是食饵和捕食者的扩散系数, 其他生物意义参考文献[1].
$ 令U = \left( {1 + av} \right)u,V = \left( {1 + \beta u} \right)v. $ |
因为
$ \left\{ \begin{array}{l} - \Delta U = u\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right),\;\;\;\;\;x \in \mathit{\Omega ,}\\ - \Delta V = v\left( {b - \frac{{dv}}{{{k_2} + u}}} \right),\;\;\;\;\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ U = V = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (2) |
其中, (u, v)为(U, V)的函数.显然式(2) 存在平凡解(0, 0).此外, 若a>λ1, 则式(2) 存在半平凡解(U*, V*)=(θa, 0);若b>λ1, 则式(2) 存在半平凡解
考察如下特征值问题[3]
$ - \Delta \varphi + q\left( x \right)\varphi = \lambda \varphi ,x \in \mathit{\Omega ,}\varphi \mathit{ = }0,x \in \partial \mathit{\Omega }\mathit{.} $ | (3) |
设
$ 0\mathit{ < }{\lambda _1}\left( q \right) < {\lambda _2}\left( q \right) \le {\lambda _3}\left( q \right) \le \cdots \to \infty . $ | (4) |
相应的特征函数为φ1, φ2, …, 其主特征值
$ {\lambda _1}\left( q \right) = \mathop {\inf }\limits_{\varphi \in H_0^1,\left\| \varphi \right\| = 1} \left\{ {{{\left\| {\nabla \varphi } \right\|}^2} + \int_\mathit{\Omega } {q\left( x \right){\varphi ^2}{\rm{d}}x} } \right\}. $ | (5) |
是单重的.而且, 有如下比较定理:若q1≥q2, 则λj(q1)≥λj(q2), 且若
考虑单个方程
$ - \Delta u + q\left( x \right)u = u\left( {a - u} \right),x \in \mathit{\Omega },u = 0,x \in \mathit{\Omega }. $ | (6) |
由文献[3]和[17]知:若a≤λ1(q(x)), 则u=0是式(6) 的唯一非负解; 而当a>λ1(q(x))时, 式(6) 存在唯一正解.当q(x)=0, a>λ1时把这个唯一正解记为θa.特别地, θa关于a严格单调递增且连续可微.∀x∈Ω, 有0 < θa < a.
设E是一个Banach空间, W⊂E称为一个楔, 如果W是一个非空闭凸集, 并且∀β≥0, 都有βW⊂W.若W是楔, 并且W∩(-W)=0, 则W是E中的一个锥.设W⊂E是一个楔, 对于y⊂W, 定义
$ {W_y} = \left\{ {x \in E:\exists r > 0,{\rm{s}}.{\rm{t}}.y + rx \in W} \right\},{S_y} = \left\{ {x \in {{\bar W}_y}\left| { - x \in {{\bar W}_y}} \right.} \right\}. $ |
引理1[18] 令q(x)∈C(Ω), 且u≥0, μ∈0(x∈Ω).则有
(ⅰ)如果0∈-Δφ+q(x)φ≤0, 那么λ1(q(x)) < 0;
(ⅱ)如果0∈-Δφ+q(x)φ≥0, 那么λ1(q(x))>0;
(ⅲ)如果-Δφ+q(x)φ≡0, 那么λ1(q(x))=0.
记r(T)是Banach空间上的线性算子T的谱半径.
引理2[15] 令q(x)∈C(Ω), P为正常数使得∀x∈Ω, -q(x)+P>0.那么以下结论成立:
(ⅰ) λ1(q(x)) < 0
(ⅱ) λ1(q(x))>0
(ⅲ) λ1(q(x))=0
引理3[2, 18] 设W是E中的一个楔, A:W→W是紧映射, 且存在不动点y0∈W, 使得Ay0=y0.令L=A′(y0)是A在y0处的Fréchet导数, 则L:Wy0→Wy0.如果I-L在E上可逆, 并且
(ⅰ) L在Wy0上具有α性质, 则indexW(A, y0)=0;
(ⅱ) L在Wy0上不具有α性质, 则indexW(A, y0)=(-1)σ, 其中σ是L大于1的特征值的代数重数之和.
则称L具有α性质, 是指如果存在t∈(0, 1), w∈Wy\Sy, 使得w-tLw∈ Sy, Wy, Sy的定义如前面所述.
2 先验估计定理1 设a, b>λ1.若(U, V)是式(2) 的任一正解,则∀x∈Ω, 有
$ 0 < u\left( x \right) < U\left( x \right) \le M = M\left( a \right): = \left[ {1 + \frac{{a\alpha }}{c}\left( {{k_1} + a} \right)} \right]a, $ |
$ 0 < v\left( x \right) < V\left( x \right) \le R = R\left( b \right): = \frac{b}{d}\left( {1 + \beta M} \right)\left( {{k_2} + M} \right). $ |
证明 设存在x1∈Ω, 使得
$ 0 \le - \Delta U\left( {{x_1}} \right) = u\left( {{x_1}} \right)\left( {a - u\left( {{x_1}} \right) - \frac{{cv\left( {{x_1}} \right)}}{{{k_1} + u\left( {{x_1}} \right)}}} \right), $ |
从而有
$ u\left( {{x_1}} \right) < a,v\left( {{x_1}} \right) < \frac{a}{c}\left( {{k_1} + u\left( {{x_1}} \right)} \right). $ |
因此有
$ U\left( x \right) \le U\left( {{x_1}} \right) = \left( {1 + \alpha v\left( {{x_1}} \right)} \right)u\left( {{x_1}} \right) < \left[ {1 + \frac{{a\alpha }}{c}\left( {{k_1} + u\left( {{x_1}} \right)} \right)} \right]u\left( {{x_1}} \right) < \left[ {1 + \frac{{a\alpha }}{c}\left( {{k_1} + a} \right)} \right]a. $ |
同理可得
$ V\left( x \right) \le V\left( {{x_2}} \right) = \left( {1 + \beta u\left( {{x_2}} \right)} \right)v\left( {{x_2}} \right) < \left( {1 + \beta u\left( {{x_2}} \right)} \right) \cdot \frac{b}{d}\left( {{k_2} + u\left( {{x_2}} \right)} \right) < \frac{b}{d}\left( {1 + \beta M} \right)\left( {{k_2} + M} \right). $ |
定理2 如果a≤λ1或b≤λ1时, 那么式(2) 没有正解.
证明 假设式(2) 存在正解(U, V), 由式(2) 关于U的方程可得
$ - \Delta U = \frac{U}{{1 + \alpha v}}\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right) < aU. $ |
两边同时乘以U, 结合格林公式得
$ \int_\mathit{\Omega } {{{\left| {\nabla U} \right|}^2}{\rm{d}}x} = \left\| {\nabla U} \right\|_2^2 < a\left\| U \right\|_2^2. $ |
由Poincaré不等式‖∇U‖22≥λ1‖U‖22得a>λ1.同理可得b>λ1.因此当a≤λ1或b≤λ1时, 式(2) 没有正解.
3 正解的存在性引入以下记号:E=C0(Ω)⊕C0(Ω), 其中C0(Ω)={u∈C(Ω):u=0, x∈∂Ω}; W=K⊕K, 其中K={u∈C0(Ω):u(x)≥0, x∈Ω}; D={(u, v)∈E:u≤M+1, V≤R+1};D′=(intD)∩W.
定义算子A:D′→W,即
$ \begin{array}{*{20}{c}} {A\left( {U,V} \right) = {{\left( { - \Delta + P} \right)}^{ - 1}}\left( {\begin{array}{*{20}{c}} {U\left\{ {P + \frac{1}{{1 + \alpha v}}\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right)} \right\}}\\ {V\left\{ {P + \frac{1}{{\beta u}}\left( {b - \frac{{du}}{{{k_2} + u}}} \right)} \right\}} \end{array}} \right) = }\\ {{{\left( { - \Delta + P} \right)}^{ - 1}}\left( {\begin{array}{*{20}{c}} {F\left( {u,v} \right) + PU}\\ {G\left( {u,v} \right) + PV} \end{array}} \right),} \end{array} $ |
其中
$ F\left( {u,v} \right) = u\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right),G\left( {u,v} \right) = v\left( {b - \frac{{du}}{{{k_2} + u}}} \right). $ |
P是充分大的常数, 使得
$ P + \frac{1}{{1 + \alpha v}}\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right) > 0,P + \frac{1}{{1 + \beta u}}\left( {b - \frac{{du}}{{{k_2} + u}}} \right) > 0 $ |
由极大值原理知(-Δ+p)-1是一个紧线性正映射, A全连续且Fréchet可导.则A的正不动点就是方程(2) 的正解.显然式(2) 存在平凡解(0, 0), 此外, 若a>λ1, 则式(2) 存在半平凡解(U*, V*)=(θa, 0);若b>λ1, 则式(2) 存在半平凡解(U*, V*)=
$ A'\left( {U,V} \right) = {\left( { - \Delta + P} \right)^{ - 1}}\left[ {P + \left( {\begin{array}{*{20}{c}} {{F_u}}&{{F_v}}\\ {{G_u}}&{{G_v}} \end{array}} \right)\left( {\begin{array}{*{20}{c}} {{u_U}}&{{u_V}}\\ {{v_U}}&{{v_U}} \end{array}} \right)} \right], $ |
其中
$ \left( {\begin{array}{*{20}{c}} {{F_u}}&{{F_v}}\\ {{G_u}}&{{G_v}} \end{array}} \right) = \left( {\begin{array}{*{20}{c}} {a - 2u - \frac{{c{k_1}v}}{{{{\left( {{k_1} + u} \right)}^2}}}}&{ - \frac{{cv}}{{{k_1} + u}}}\\ {\frac{{d{v^2}}}{{{{\left( {{k_2} + u} \right)}^2}}}}&{b - \frac{{2dv}}{{{k^2} + u}}} \end{array}} \right), $ |
$ \left( {\begin{array}{*{20}{c}} {{u_U}}&{{u_V}}\\ {{v_U}}&{{v_U}} \end{array}} \right) = {\left( {\begin{array}{*{20}{c}} {1 + \alpha v}&{\alpha u}\\ {\beta v}&{1 + \beta u} \end{array}} \right)^{ - 1}} = \frac{1}{{1 + \alpha v + \beta u}}\left( {\begin{array}{*{20}{c}} {1 + \beta u}&{ - \alpha u}\\ { - \beta v}&{1 + \alpha v} \end{array}} \right), $ |
因此可以得到
$ A'\left( {U,V} \right) = {\left( { - \Delta + P} \right)^{ - 1}}\left[ {P + \frac{1}{{1 + \alpha v + \beta u}}\left( {\begin{array}{*{20}{c}} {a - 2u - \frac{{c{k_1}}}{{v{{\left( {{k_1} + u} \right)}^2}}}}&{ - \frac{{cv}}{{{k_1} + u}}}\\ {\frac{{d{v^2}}}{{{{\left( {{k_2} + u} \right)}^2}}}}&{b - \frac{{2dv}}{{{k^2} + u}}} \end{array}} \right)\left( {\begin{array}{*{20}{c}} {1 + \beta u}&{ - \alpha u}\\ { - \beta v}&{1 + \alpha v} \end{array}} \right)} \right]. $ |
引理4 假设a>λ1, 则有
(ⅰ)若b≠0, 则indexW(A, (0, 0))=0;
(ⅱ)若
证明 (ⅰ)令L=A′(0, 0), 其中A′(0, 0) 是A在(0, 0) 处的Fréchet导数.直接计算得W(0, 0)=W, S(0, 0)=(0, 0),
$ L = {\left( { - \Delta + P} \right)^{ - 1}}\left( {\begin{array}{*{20}{c}} {a + P}&0\\ 0&{b + P} \end{array}} \right). $ |
先证明I-L在W(0, 0)上可逆.如果存在(ξ, η)∈W(0, 0), 使得L(ξ, η)T=(ξ, η)T,则有-Δξ=aξ, x∈Ω, ξ=0, x∈∂Ω.如果ξ>0, 则a=λ1, 矛盾.故ξ≡0.同理η≡0.这说明I-L在W(0, 0)上可逆.
接着证明L具有α性质.因为a>λ1, 由引理2知, ra=r[(-Δ+P)-1(a+P)]>1, 同时ra是算子(-Δ+P)-1(a+P)的主特征值, 对应的特征函数φ>0, 取t0=ra-1, 则0 < t0 < 1且(I-t0L)(φ, 0)T=(0, 0)T∈S(0, 0).因此L具有α性质.由引理3知indexW(A, (0, 0))=0.
(ⅱ)若
$ L = \left( { - \Delta + P} \right)\left( {\begin{array}{*{20}{c}} {P + a - 2{\theta _a}}&{ - \frac{{\alpha {\theta _a}\left( {a - 2{\theta _\alpha }} \right)\left( {{k_1} + {\theta _a}} \right) + c{\theta _a}}}{{\left( {1 + \beta {\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right)}}}\\ 0&{P + \frac{b}{{1 + \beta {\theta _a}}}} \end{array}} \right). $ |
首先证明I-L在W(θa, 0) 上可逆.假定存在(ξ, η)∈W(θa, 0), 使L(ξ, η)T=(ξ, η)T.则有
$ \left\{ \begin{array}{l} - \Delta \xi = \left( {a - 2{\theta _a}} \right)\xi - \frac{{\alpha {\theta _a}\left( {a - 2{\theta _\alpha }} \right)\left( {{k_1} + {\theta _a}} \right) + c{\theta _a}}}{{\left( {1 + \beta {\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right)}}\eta ,\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ - \Delta \eta = \frac{b}{{1 + \beta {\theta _a}}}\eta ,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ \xi = \eta = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (7) |
如果η>0, 由式(7) 的第2个方程知
$ \left\{ \begin{array}{l} - \Delta \xi = \left( {a - 2{\omega _a}} \right)\xi ,\;\;\;x \in \mathit{\Omega ,}\\ \xi = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (8) |
如果ξ≠0, 则λ1(2θa-a)≤0.由特征值的相关性质知λ1(2θa-a)>λ1(θa-a)=0, 矛盾.故ξ≡0, 故I-L在W(θa, 0)上可逆.
接着证明L在W(θa, 0)具有α性质.因为
$ \begin{array}{l} \left( {I - tL} \right)\left( {\begin{array}{*{20}{c}} 0\\ \varphi \end{array}} \right) = \left( {\begin{array}{*{20}{c}} {t{{\left( { - \Delta + P} \right)}^{ - 1}}\frac{{\alpha {\theta _a}\left( {a - 2{\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right) + c{\theta _a}}}{{\left( {1 + \beta {\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right)}}\varphi }\\ {\varphi - t{{\left( { - \Delta + P} \right)}^{ - 1}}\left( {P + \frac{b}{{1 + \beta {\theta _a}}}} \right)\varphi } \end{array}} \right) = \\ \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\left( {\begin{array}{*{20}{c}} {t{{\left( { - \Delta + P} \right)}^{ - 1}}\frac{{\alpha {\theta _a}\left( {a - 2{\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right) + c{\theta _a}}}{{\left( {1 + \beta {\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right)}}\varphi }\\ 0 \end{array}} \right). \end{array} $ |
故(I-tL)(0, φ)T∈S(θa, 0), 因此L在W(θa, 0)上具有α性质.由引理3知, indexW(A, (θa, 0))=0.
由前面的证明知I-L在W(θa, 0)上可逆.现在证明L在W(θa, 0)上不具有α性质.因为
假设1/μ是L的一个特征值, 对应的特征函数记为(ξ, η), 有
$ \left\{ \begin{array}{l} - \Delta \xi + P\xi = \mu \left( {\left( {P + a - 2{\theta _a}} \right)\xi - \frac{{\alpha {\theta _a}\left( {a - 2{\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right) + c{\theta _a}}}{{\left( {1 + \beta {\theta _a}} \right)\left( {{k_1} + {\theta _a}} \right)}}\eta } \right),\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ - \Delta \eta + P\eta = \mu \left( {P + \frac{b}{{1 + \beta {\theta _a}}}} \right)\eta ,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ \xi = \eta = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (9) |
如果η
$ 0 = {\lambda _j}\left( {P\left( {1 - \mu } \right) + \mu \left( { - \frac{b}{{1 + \beta {\theta _a}}}} \right)} \right) \ge {\lambda _1}\left( {P\left( {1 - \mu } \right) + \mu \left( { - \frac{b}{{1 + \beta {\theta _a}}}} \right)} \right) > {\lambda _1}\left( { - \frac{b}{{1 + \beta {\theta _a}}}} \right). $ |
对于j≥1, 此与
类似可以证明引理4成立.
引理5 假设b>λ1, 则有
(ⅰ)若
(ⅱ)若
引理6 indexW(A, D′)=1.
证明 ∀t∈[0, 1], 定义
$ {A_t}\left( {U,V} \right) = {\left( { - \Delta + P} \right)^{ - 1}}\left( {\begin{array}{*{20}{c}} {tF\left( {u,v} \right) + PU}\\ {tG\left( {u,v} \right) + PV} \end{array}} \right), $ |
那么At(U, V):[0, 1]×D→W是正的紧算子, 且A=A1.显然在∂D上A没有不动点.故indexW(A, D′)有意义.对任意的t, At的不动点是下述方程的解:
$ \left\{ \begin{array}{l} \Delta U = tu\left( {a - u - \frac{{cv}}{{{k_1} + u}}} \right),\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ - \Delta V = tv\left( {b - \frac{{dv}}{{{k_2} + u}}} \right),\;\;\;\;\;\;\;\;\;x \in \mathit{\Omega ,}\\ U = V = 0,\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;x \in \partial \mathit{\Omega }\mathit{.} \end{array} \right. $ | (10) |
由定理1知, ∀t∈[0, 1], At的不动点满足u≤M, v≤R, 因此At的不动点一定落在D内.由度的同伦不变性知indexW(A, D′)=indexW(A1, D′)=indexW(A0, D′).又因为当t=0时, 方程(10) 仅有平凡解(0, 0), 故indexW(A0, D′)=indexW(A0, (0, 0)).记
$ L = {{A'}_0}\left( {0,0} \right) = {\left( { - \Delta + P} \right)^{ - 1}}\left( {\begin{array}{*{20}{c}} P&0\\ 0&P \end{array}} \right), $ |
由引理2易知r(L) < 1, 因此I-L在W(0, 0)上可逆且L在W(0, 0)上不具有α性质.故indexW(A, D′)=1.
定理3 若a>λ1,
证明 若式(2) 除了(0, 0), (θa, 0),
$1 = {\rm{inde}}{{\rm{x}}_W}\left( {A,D'} \right) = {\rm{inde}}{{\rm{x}}_W}\left( {A,\left( {0,0} \right)} \right) + {\rm{inde}}{{\rm{x}}_W}\left( {A,\left( {0,\frac{{{k_2}}}{d}{\theta _b}} \right)} \right) = 0,$ |
矛盾.因此, 若a>λ1,
[1] | AZIZ-ALAOUI M A, OKIYE M D. Boundedness and global stability for a predator-prey model with modified Leslie-Gower and Holling-Type Ⅱ Schemes[J]. Appl Math Lett, 2003, 16(7): 1069-1075 DOI:10.1016/S0893-9659(03)90096-6 |
[2] |
袁海龙, 李艳玲. 一类捕食食饵模型共存解的存在性与稳定性[J].
陕西师范大学学报(自然科学版), 2014, 42(1): 15-19 YUAN Hailong, LI Yanling. Coexistence of existence and stability of a predator-prey model[J]. Journal of Shaanxi Normal University(Natural Science Edition), 2014, 42(1): 15-19 |
[3] |
孟丹, 李艳玲. 一类具有修正的Leslie型功能反应的捕食-食饵模型[J].
纺织高校基础科学学报, 2016, 29(1): 11-17 MENG Dan, LI Yanling. A predator-prey model of modified Leslie type functional response[J]. Basic Sciences Journal of Textile Universities, 2016, 29(1): 11-17 |
[4] |
张岳, 李艳玲. 带有交叉扩散项的Holling type Ⅱ捕食-食饵模型的共存[J].
纺织高校基础科学学报, 2010, 23(4): 439-445 ZHANG Yue, LI Yanling. Coexistnce of predator-prey model wih cross-diffusion and Holling type Ⅱ functional response[J]. Basic Sciences Journal of Textile Universities, 2010, 23(4): 439-445 |
[5] | JIA Yunfeng, WU Jianhua, XU Hongkun. Positive solutions of a Lotka-Volterra competition model with cross-diffusion[J]. Comput Math Appl, 2014, 68(10): 1220-1228 DOI:10.1016/j.camwa.2014.08.016 |
[6] | KUTO K, YAMADA Y. Coexistence problem for a prey-predator model with density-dependent diffusion[J]. Nonlinear Anal, 2009, 71(12): 2223-2232 DOI:10.1016/j.na.2009.05.014 |
[7] | RYU K, AHN I. Coexistence states of a nonlinear Lotka-Volterra type predator-prey model with cross-diffusion[J]. Nonlinear Anal, 2009, 71(12): 1109-1115 DOI:10.1016/j.na.2009.01.097 |
[8] | XU Qian, GUO Yue. The existence and stability of steady states for a prey-predator system with cross diffusion of quasilinear fractional type[J]. Acta Math Appl Sin Engl Ser, 2014, 30(1): 257-270 DOI:10.1007/s10255-014-0281-3 |
[9] |
何堤, 容跃堂, 张晓晶. 一类具有交叉扩散的捕食-食饵模型的分歧[J].
纺织高校基础科学学报, 2015, 28(4): 425-431 HE Di, RONG Yuetang, ZHANG Xiaojing. Bifurcation for a kind of prey-predator model with cross-diffusion[J]. Basic Sciences Journal of Textile Universities, 2015, 28(4): 425-431 |
[10] | RYU K, AHN I. Coexistence theorem of steady states for nonlinear self-cross diffusion systems with competitive dynamics[J]. J Math Anal Appl, 2003, 283(1): 46-65 DOI:10.1016/S0022-247X(03)00162-8 |
[11] | KUTO K, YAMADA Y. Multiple coexistence states for a prey-predator system with cross-diffusion[J]. J Differential Equations, 2004, 197(2): 315-348 DOI:10.1016/j.jde.2003.08.003 |
[12] | LOU Yuan, NI Weiming. Diffusion vs cross-diffusion:An elliptic approach[J]. J Differential Equations, 1999, 154(1): 157-190 DOI:10.1006/jdeq.1998.3559 |
[13] | NAKASHIMA K, YAMADA Y. Positive steady states for prey-predator models with cross-diffusion[J]. Adv Differential Equations, 1996, 1(6): 1099-1122 |
[14] | CHEN Xinfu, QI Yuanwei, WANG Mingxin. A strongly coupled predator-prey system with non-monotonic functional response[J]. Nonlinear Anal, 2007, 67(6): 1966-1979 DOI:10.1016/j.na.2006.08.022 |
[15] | WANG Mingxin, WANG Xubo. Existence, uniqueness and stability of positive steady states to a prey-predator diffusion system[J]. Sci China Ser A, 2009, 52(5): 1031-1041 DOI:10.1007/s11425-008-0162-4 |
[16] | WANG Lingshu, XU Rui, GUANG Huifeng. A stage-structured predator-prey system with impulsive effect and Holling type-Ⅱ functional response[J]. Journal of Mathematical Research, 2011, 31(1): 147-156 |
[17] |
叶其孝, 李正元, 王明新, 等.
反应扩散方程引论[M]. 北京: 科学出版社, 1990: 40-56.
YE Qixiao, LI Zhengyuan, WANG Mingxin, et al. Introduction to reaction-diffusion equations[M]. Beijing: Science Press, 1990: 40-56. |
[18] | KO W, RYU K. Coexistence states of a predator-prey system with non-monotonic functional response[J]. Nonlinear Analysis.Real World Applications, 2007, 8(3): 769-786 DOI:10.1016/j.nonrwa.2006.03.003 |