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本文讨论一般非均匀凸介质所确定的迁移算子的本征值的分布问题,利用Hilbert空间的H算子理论,完整地解决了一般非均匀凸介质中迁移算子本征值的分布问题,若{λn}n=1^∞是迁移算子本征值的一种计数,我们证明了Σ↓n=1↑∞e^6Reλnτ〈+∞,其中τ是粒子的最大逃逸时间,并对本征值的发散程度以及本征值的个数函数作了相应的讨论。 相似文献
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本文在Lp(1(≤)p<+∞)空间上,研究了种群细胞增生中一类具非光滑边界条件的Rotenberg模型,讨论了这类模型相应的迁移算子的谱分析,证明了该迁移算子的本征值的存在性,得到了该迁移算子的谱在某半平面上仅由有限个具有限代数重数的离散本征值组成等结果. 相似文献
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本文对有界凸的非均匀介质中具各向异性散射和裂变的连续能量中子迁移的非定态方程,将方向和能量两个变量同时离散的所谓离散纵标——多群逼近方法建立起系统的数学理论,证明了: 1 非定态迁移方程的解,可由相应的非定态离散纵标——多群迁移系统的解逼近。 2 原迁移算子的占优本征值,可由离散纵标——多群迁移算子所确定的具非负本征函数且实部为最大的本征值逼近。 3 原迁移算子的占优本征值所相应的正本征函数,可由离散纵标——多群迁移算子的实部为最大的本征值所相应的非负本征函数逼近。 4 估计了各种逼近的阶。 相似文献
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在LP(1 P<∞)空间研究了板模型中一类带广义边界条件具各向异性、连续能量、均匀介质迁移算子的谱,证明了该迁移算子生成C0半群的D yson—Ph illips展开式的二阶余项在LP(1
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运用线性算子理论,研究了板模型中具抽象边界条件的各向异性和连续能量的迁移算子的谱.采用比较算子和豫解算子等方法证明了这类迁移算子产生的C_0半群的Dyson-phillips展开式的第9阶余项的弱紧性,得到了该迁移算子的谱在某区域Γ中仅由有限个具有限代数重数的离散本征值组成. 相似文献
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板几何中具反射边界条件的迁移算子的谱分析 总被引:1,自引:0,他引:1
在Lp(1 p<∞)空间上研究了板几何中具反射边界条件下各向异性、连续能量、非均匀介质的迁移方程,证明了该迁移算子产生C0半群的Dyson-Phillips展开式的二阶余项在Lp(1
相似文献
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In this communication, evidence is presented from the kinetics of QA
– decay (where QA is the first plastoquinone electron acceptor of photosystem II) and oxygen evolution for the requirement of bicarbonate in the electron transport in a cyanobacteriumSynechocystis (Pasteur Culture Collection 6803). A large slowing down of QA
– oxidation, measured from the variable chlorophylla fluorescence after saturating actinic flashes, was observed in the thylakoids ofSynechocystis 6803 depleted of bicarbonate in the presence of 25 mM formate. Qualitatively similar results were obtained with DCMU-treated thylakoids. This shows that bicarbonate depletion inhibits electron transport on the acceptor side of photosystem II between QA and the plastoquinone (PQ) pool in cyanobacteria. Addition of 2.5 mM HCO3
– fully reversed the inhibition of electron flow caused by bicarbonate depletion. Two exponential phases of QA
– decay, a fast one and a slow one, were observed with halftimes of approx. 400 s (fast) and 26 ms (slow) at pH 6.5. At pH 7.5, these phases were approx. 330 s (fast) and 21 ms (slow), respectively. The amplitude, but not the halftime, of the fast component decreased by about 70% (pH 6.5) or 50% (pH 7.5); this was accompanied by a concomittant increase in the slow phase. Twenty mM bicarbonate stimulated, by a factor of 4, the Hill reaction in bicarbonate-depletedSynechocystis cells. This effect is independent of CO2 fixation as it was observed even in the presence of an inhibitor DBMIB.Abbreviations Chl
Chlorophyll
- DBMIB
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- DMQ
2,5-dimethyl-p-benzoquinone
- S13
5-Cl, 3-t-butyl, 2-Cl, 4-NO2-salicylanilide
- PCC
Pasteur culture collection 相似文献
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Yang Li Guohui Cao Ruifei Duan Guangcan Che Zhongxian Zhao J. A. Larrea J E. M. Baggio-Saitovitch 《中国科学A辑(英文版)》2000,43(4):400-406
119Sn M?ssbauer research is carried out on (La1-xSrx),Cu1-xSnxO4(x = 0.075 and 0.110) superconductors which are designed under a new concept. The M?ssbauer spectra results show that Sn occupies
Cu position in Sn4+ state, and there is no Sn2+ ion occupying La position. The local lattice deformation near Sn4+ site is small, but displays an increasing tendency with Sn doping. For La2CuO4 matrix, the simultaneous dopings of Sr/Sn induce holes and electrons on CuO2 layer in a new mechanism which influences superconductivity. Under a new mechanism of extra oxygen, the extra oxygen effect
of Sn-doping on superconductivity is discussed 相似文献
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Meiya Li Guangcheng Xiong Zhonglie Wang Shoushan Fan Qingtai Zhao Kuixun Lin 《中国科学A辑(英文版)》1999,42(8):865-872
Epitaxial growth of the La0.5Sr0.5
3(LO) thin films has been realized on Lin3, SrTiC3 and MgO substrates by pulsed laser deposition. The epitaxial growth behavior and the electrical transport properties of these
films were studied systematically. The temperature dependencies of the resistivity of the film have been determined. Studies
indicate that close dependencies exist between the crystal structures and the electrical transport properties of the epitaxial
LSCO films, and that the epitaxial thin films are of low resistivity and metallic conductive features. The epitaxial films
deposited on the LaA103 substrates at about 700 °C possess the optimal properties compared with the others. Discussions of the dependencies and the
mechanisms of the epitaxial structures on the electrical transport properties of the LSCO films have been made.
Project supported by the National Natural Science Foundation of China (Grant No. 19574003 and No. 19674001). 相似文献
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The estimation of the location parameter of an ℓ1-symmetric distribution is considered. Specifically when a p-dimensional random vector has a distribution that is a mixture of uniform distributions on the ℓ1-sphere, we investigate a general class of estimators of the form δ=X+g. Under the usual quadratic loss, domination of δ over X is obtained through the partial differential inequality 4 div g+2X
∂2g+ g20 and a new superharmonicity-type-like notion adapted to the ℓ1-context. Specifically the condition of ℓ1-superharmonicity is that 2Δf+X
3f0 and div 3f0 as compared to the usual (ℓ2) condition Δf0. 相似文献
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Riping Liu Jianhua Zhao Xiangyi Zhang Duanwei He Zhicheng Qin Yingfan Xu Wenkui Wang 《中国科学A辑(英文版)》1999,42(1):74-79
The microstructure of Pd77.5Au6Si16.5alloy solidified both on board a Chinese Retrievable Satellite and on the earth is studied. Postmortem analyses of microstructure
presented that the same types of phases, primary phase (Pd3Si) and eutectics (Pd3Si + Pd solid solution) were formed in both cases. But the phase morphologies were quite different. It was dendritic for the
primary phase and lamellar for the eutectics under normal gravity condition. However, under microgravity condition the primary
phase was granular and the eutectic was peculiar network. Detailed analysis showed that the differences in morphologies of
the microstructure were due to the existence of gravity-induced buoyancy convection on the earth which increased the mass
transport abilities and decreased the thickness of the solute boundary in front of the solid-liquid interface during solidification
under normal gravity condition. 相似文献
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The main purpose of this article is to introduce particular subsets of R I , which are not necessarily convex, and we call them I m -quasi upward, or I m -quasi downward. We show that these sets can be translated to downward or upward sets. We introduce the connection of these sets with downward and upward subsets of R I , and discuss the best approximation of these sets. Also we introduce embedded I m -quasi upward and embedded I m -quasi downward subsets of a normed space X. 相似文献
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讨论Banach空间几种超投影性质(及其相应的局部化性质)之间的关系,证明了在Banach空间X自反的条件下,X是lp-次投影空间的充要条件是X*是lp-超投影空间,X是局部lp-次投影空间的充要条件是X*是局部lp-超投影空间,以及X是局部次投影空间的充要条件是X*是局部超投影的。其中1/p+1/q=1(p>1,q>1)。 相似文献
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Let R be a commutative (possibly non-Noetherian) ring (in order to make things less technical) and C a semidualizing R-module. In this article, we introduce and investigate the notion of G C -injective (G C -projective) complexes. This extends Enochs and García Rozas's notion of Gorenstein injective (Gorenstein projective) complexes. We then show that a complex X is G C -injective (G C -projective) if and only if X m is a G C -injective (G C -projective) module for each m ∈ ?. 相似文献
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A. M. Voloshchenko 《Computational Mathematics and Mathematical Physics》2009,49(2):334-362
For the transport equation in three-dimensional (r, ?, z) geometry, a KP1 acceleration scheme for inner iterations that is consistent with the weighted diamond differencing (WDD) scheme is constructed. The P 1 system for accelerating corrections is solved by an algorithm based on the cyclic splitting method (SM) combined with Gaussian elimination as applied to auxiliary systems of two-point equations. No constraints are imposed on the choice of the weights in the WDD scheme, and the algorithm can be used, for example, in combination with an adaptive WDD scheme. For problems with periodic boundary conditions, the two-point systems of equations are solved by the cyclic through-computations method elimination. The influence exerted by the cycle step choice and the convergence criterion for SM iterations on the efficiency of the algorithm is analyzed. The algorithm is modified to threedimensional (x, y, z) geometry. Numerical examples are presented featuring the KP1 scheme as applied to typical radiation transport problems in three-dimensional geometry, including those with an important role of scattering anisotropy. A reduction in the efficiency of the consistent KP1 scheme in highly heterogeneous problems with dominant scattering in non-one-dimensional geometry is discussed. An approach is proposed for coping with this difficulty. It is based on improving the monotonicity of the difference scheme used to approximate the transport equation. 相似文献