共查询到18条相似文献,搜索用时 234 毫秒
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将血浆中PaCO2作为自变量、△[HCO3-]/△PaCO2作为因变量,对慢性呼吸性酸碱平衡紊乱时,肾的代偿调节作用进行了量化处理.根据两者间的量化关系,看到:慢性呼吸性酸中毒时,随着血浆中PaCO2值越来越大,△[HCO3-]/△PaCO2的变化率越来越小;慢性呼吸性碱中毒时,随着血浆中PaCO2值越来越小,△[HCO3-]/△PaCO2的变化率也越来越小.这些结果完全符合生物学规律.提示这一量化处理对研究慢性呼吸性酸碱平衡紊乱时,肾代偿调节机制、代偿强度等有一定的意义. 相似文献
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将血浆中[HCO3-]作为自变量、△PaCO2/△[HCO3-]作为因变量,对酸碱平衡紊乱中肺的缓冲作用进行了量化处理并初步建立了数学模型.利用两者间的函数关系,看到:代谢性酸中毒时,随着血浆中[HCO3-]值越来越小,△PaCO2/△[HCO3-]的变化率也越来越小;代谢性碱中毒时,随着血浆中[HCO3-]值越来越大,△PaCO2/△[HCO3-]的变化率越来越小.这一结果完全符合生物学规律.提示这一数学模型对研究酸碱平衡紊乱时,肺代偿调节机制、代偿强度等情况有一定的意义. 相似文献
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设Z,N分别是全体整数和正整数的集合,Mm(Z)表示Z上m阶方阵的集合.本文运用Fermat大定理的结果证明了:对于取定的次数n∈N,n≥3,二阶矩阵方程Xn+Yn=λnI(λ∈Z,λ≠0,X,Y∈M2(Z),且X有一个特征值为有理数)只有平凡解;利用本原素因子的结果得到二阶矩阵方程Xn+Yn=(±1)nI(n∈N,n≥3,X,Y∈M2(Z))有非平凡解当且仅当n=4或gcd(n,6)=1且给出了全部非平凡解;通过构造整数矩阵的方法,证明了下面的矩阵方程有无穷多组非平凡解:■n∈N,Xn+Yn=λnI(λ∈Z,λ≠0,X,Y∈Mn(Z));X3+Y3=λ3I(λ∈Z,λ≠0,m∈N,m≥2,X,Y∈Mm(Z)). 相似文献
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We derive the solvability conditions and an expression of the general solution to the system of matrix equations A 1X=C1 , A2Y=C2 , YB2=D2 , Y=Y*, A3Z=C3 , ZB3=D3 , Z=Z*, B4X+(B4X)+C4YC4*+D4ZD4*=A4 . Moreover, we investigate the maximal and minimal ranks and inertias of Y and Z in the above system of matrix equations. As a special case of the results, we solve the problem proposed in Farid, Moslehian, Wang and Wu’s recent paper (Farid F O, Moslehian M S, Wang Q W, et al. On the Hermitian solutions to a system of adjointable operator equations. Linear Algebra Appl, 2012, 437: 1854-1891). 相似文献
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Let X1,X2,...,Xk be k disjoint subsets of S with the same cardinality m.Define H(m,k) = {X (C) S: X (C) Xi for 1 ≤I ≤k} and P(m,k) = {X (C) S : X ∩ Xi ≠φ for at least two Xi's}.Suppose S = Uki=1 Xi,and let Q(m,k,2) be the collection of all subsets K of S satisfying|K ∩ Xi|≥ 2 for some 1 ≤ I ≤ k.For any two disjoint subsets Y1 and Y2 of S,we define F1,j = {X (C) S : either |X ∩ Y1|≥ 1 or |X ∩ Y2|≥ j}.It is obvious that the four posers are graded posets ordered by inclusion.In this paper we will prove that the four posets are nested chain orders. 相似文献
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Let {A, B} and {C, D} be diagonalizable pairs of order n, i.e., there exist invertible matrices P, Q and X, Ysuchthat A = P∧Q, B = PΩQ, C =XГY, D= X△Y, where
∧ = diag(α1, α2, …, αn), Ω= diag(βl, β2, …βn),
Г=diag(γ1,γ2,…,γn), △=diag(δl,δ2,…,δn).
Let ρ((α,β), (γ,δ))=|αδ-βγ|/√|α|^2+|β|^2√|γ|^2+|δ|^2.In this paper, it will be proved that there is a permutation τ of {1,2,... ,n} such that
n∑i=1[ρ((αi,βi),(γτ(i),δτ(i)))]^2≤n[1-1/κ^2(Y)κ^2(Q)(1-d2F(Z,W)/n)],
where κ(Y) = ||Y||2||Y^-1||2,Z= (A,B),W= (C, D) and dF(Z,W) = 1/√2||Pz* -Pw*||F. 相似文献
∧ = diag(α1, α2, …, αn), Ω= diag(βl, β2, …βn),
Г=diag(γ1,γ2,…,γn), △=diag(δl,δ2,…,δn).
Let ρ((α,β), (γ,δ))=|αδ-βγ|/√|α|^2+|β|^2√|γ|^2+|δ|^2.In this paper, it will be proved that there is a permutation τ of {1,2,... ,n} such that
n∑i=1[ρ((αi,βi),(γτ(i),δτ(i)))]^2≤n[1-1/κ^2(Y)κ^2(Q)(1-d2F(Z,W)/n)],
where κ(Y) = ||Y||2||Y^-1||2,Z= (A,B),W= (C, D) and dF(Z,W) = 1/√2||Pz* -Pw*||F. 相似文献
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最小一乘线性回归(上) 总被引:44,自引:1,他引:43
1.引言 为使读者易于了解方法的要旨,而不为繁复的记号与数学推导分散掉注意力,本篇中先集中讨论只含一个自变量的线性回归的情形. 设有自变量X和因变量Y,X、Y都是一维,例如,X、Y分别是从同一个人身上量出的身高和体重.现在对X、 Y进行了。次观测,得数据 (x1,y1),(x2,y2),…,(xn,yn)(1)要作一条直线x= a bx,“最好地”代表(1)中那些点的趋势,或者说,与(1)中那些点“拟合”得最好,怎么叫拟合最好?这就要看你给出怎样的准则,最常见的准则是“最小二乘”准则,这准则要求这样决定a和b,使(1)中各点沿十轴到直线y=a bx的偏离yi-(a bx;)(i= 1,… 相似文献
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在有界光滑区域Ω∈R~N(N4)上,研究双调和方程△~2u-λu=|u|~(2_*-2)u,x∈Ω,u=(δu)/(δn)=0,x∈δΩ,其中2_*=2N/(N-4)是临界指数.对于任意的λ0,利用变分方法可以得到上面方程非平凡解的存在性. 相似文献
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本文讨论了Rn 上如下一类带临界增长的拟线性椭圆方程正解的存在性 :-div(| u|p- 2 u) -axn| u|p- 2 u xn +|u|p- 2u=up - 1 ,xn ≠ 0 ,x∈Rn.这里 ,1
相似文献
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一类非线性椭圆边值问题解的存在性 总被引:12,自引:5,他引:7
魏利 《数学的实践与认识》2001,31(3):360-364
目前 ,对 s——拉普拉斯算子△s的研究是较为活跃的数学课题 .原因在于算子 -△s与许多物理现象有关 .比如 :反射扩散问题 ,石油提取问题等等 .基于此因 ,在文 [3]的基础上 ,我们将继续研究以下非线性边值问题在 Ls(Ω) ,( 1 2 nn+1 )中解的存在条件 .-△su +g( x,u) =f几乎处处在Ω中-〈 ,| u|s- 2 u〉 =0几乎处处在Γ上其中 f∈Ls( Ω)给定 ,Ω Rn( n 1 ) ,△su=div( | u|s- 2 u) ,g∶Ω× R→ R满足 Caratheodory条件 .本文把文 [3]关于非线性边值问题 @在 Lp( Ω) ( 2 p<+∞ )空间中解的存在性的研究推广到 Ls( Ω) ( 1 2 nn+1 )空间中 . 相似文献
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ZHENG ShiJun 《分析论及其应用》2004,20(3)
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V. 相似文献
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We show that the supremum norm of solutions with small initial data of the generalized Benjamin-Bona-Mahony equation ut-△ut=(b,▽u)+up(a,▽u)in x?Rn,n≥2, with integer p≥3 , decays to zero like t-2/3 if n=2 and like t-1+6, for any δ0, if n≥3, when t tends to infinity. The proofs of these results are based on an analysis of the linear equation ut-△=(b,▽u)) and the associated oscillatory integral which may have nonisolated stationary points of the phase function. 相似文献