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1.
Suppose that P=(p\-1, p\-2, ..., p\-M)\% is a probability vector with p\-i>0 and Y={1, 2, ..., M}. Let (Y, 2\+Y, μ) be a probability space with μ(i)=p\-i, i=1, 2, ..., M, and (∑\-M, B, m)= Π \+∞\-0(Y, 2\+U, μ). It is shown that for any a \%(0≤a ≤1) \%, there exists a set U∈B such that m(U)=a and the Julia set associated with U is equal to the Julia set associated with ∑\-M\%. Moreover repelling fixed points with respect to U are dense in the Julia set associated with U.  相似文献   

2.
The paper is concerned with some chemotaxis model ∂u/∂t=D▿(u▿ln(u/w))+u(abu),∂w/∂t=f(u,w). To study the behavior of the solution, some function transformations are introduced, and the main tool is sup-sub-solution method. The result shows that, whether the solution blows up in finite time depends on the parameters and the initial data. As the chemical substance w has linear growth, f(u,w)=βuδw, where β>0, δ>0 and a+δ>0, wherein the solution exists globally. However, as w possesses exponential growth, f(u,w)=(βuδ)w, wherein both u and w share the same blowup point and time if the solution blows up in finite time. Biography: CHEN Hua(1956–), male, Professor, Ph. D., research direction: partial differential equation and its application.  相似文献   

3.
Orientational domains at room temperature in orthorhombic perovskite La0.33Ca0.67MnO3 were studied by group-theory and observed systematically using transmission electron microscopy. There are six orientational variants (A, A′, B, B′, C andC′) in orthorhombic perovskite La0.33Ca0.67MnO3. Their orthorhombicb o directions are parallel to thea p,b p andc p directions of the cubic prototypic perovskite, respectively. In each case there are two orientational variants (e.g.,A andA′) with theira o andc o axes interchanged. Among the possible 15 boundaries between these 6 variants there are only two types of domain boundaries: (1) m<100>boundariesC′/C, A′/A, andB′/B. (2) m<110>boundaryiesC′/A, C′/A′, C′/B, C′/B′, C/A, C/A′, C/B, C/B′, B′/A, B′/A′, B/A, andB/A′. Foundation item: Supported by the National Natural Science Foundation of China (19974031) and US DOE(DE-AC02-98CH10886) Biography: WANG Ren-hui (1937-), male, Professor.  相似文献   

4.
We propose a mean-field Bak-Sneppen (MFBS) model with varying interaction strength. The interaction strength, here denoted by α, specifies the degree of interaction, and varies smoothly between 0 for no interaction and 1 for full interaction (restoring the original BS model). Our simulations of the MFBS model reveal some interesting features. When α is non-zero, the MFBS model can evolve to a self-organized critical (SOC) state. The critical exponent of the avalanche size distribution, α, is insensitive to ...  相似文献   

5.
Conclusions  
(1)  The newly developed nanocrystalline Fe72 Cu1Nb2V2Sil4 B9 and Fe72Cu1NblMo1-V2Si14B9 alloy still show the superior synthetical magnetic properties quite comparable with those of the early developed and typical Fe-Cu-Nb-Si-B alloys. Their cost has been reduced, the ductility of their amorphous ribbons is much better than that of Fe-Cu-Nb-Si-B alloys, and their ribbons can be folded back without brittleness.
(2)  In the range off = 20–2000 kHz and Bm = 0.05-0.6 T, the dependences of core loss on frequency and amplitude flux density can be expressed asPoc B2 mfn,n = 1.6-1.7.
(3)  In the range of f= 20–2000 kHz and (B m f) = (15−30) × 103 T·Hz, the approximate expression 1nP = [a(Bm,f) +b] (lnf)-n is tenable, wheren =0.2-0.3, and botha andb are constant.
(4)  The newly developed nanocrystalline alloys have been used in switching mode power supply with larger output power, unipolarity pulse transformer and precision current mutual inductor and clearly shown advantage.
  相似文献   

6.
The definition of n-parameter infinite-dimensional (r,δ) -Ornstein-Uhlenbeck process {xt (·) } ((r, δ)-OUPn∞ for short) is given. The absolute continuity of distribution μt of Xt(·) and the limit of Xt(·) when |t| →∞ is discussed.  相似文献   

7.
Interplanetary shock can greatly disturb the Earth's magnetosphere and ionosphere, causing the temporal and spatial changes of the magnetic field and plasmas at the geosynchronous orbit. In this paper, we use the magnetic field data of GOES satellites from 1997 to 2007 and the plasma data of MPA on the LANL satellites from 1997 to 2004 to study the properties of magnetic field and plasma (0.03-45 keV) at the geosynchronous orbit (6.6 RE) within 3 hours before and after the arrival of shock front at the geosynchronous orbit through both case study and superposed epoch analysis. It is found that following the arrival of shock front at the geosynchronous orbit, the magnetic field magnitude, as well as GSM Bzcomponent increases significantly on the dayside (8-16 LT), while the By component has almost no change before and after shock impacts. In response to the interplanetary shock, the proton becomes much denser with a peak number density of 1.2 cm^-3, compared to the typical number density of 0.7 cm^-3. The proton temperature increases sharply, predominantly on the dusk and night side. The electron, density increases dramatically on the night side with a peak number density of 2.0 cm^-3. The inferred ionospheric O^+ density after the interplanetary shock impact reaches the maximum value of 1.2 cm^-3 on the dusk side and exhibits the clear dawn-dusk asymmetry. The peak of the anisotropy of proton's temperature is located at the noon sector, and the anisotropy decreases towards the dawn and dusk side. The minimum of temperature anisotropy is on the night side. It is suggested that the electromagnetic ion cyclotron (EMIC) wave and whistler wave can be stimulated by the proton and electron temperature anisotropy respectively. The computed electromagnetic ion cyclotron wave (EMIC) intense on the day side (8--16 LT) with a frequency value of 0.8 Hz, and the wave intensity decreases towards the dawn and dusk side, the minimum value can be found on the night side. The computed electron whistler wave locates on the day side (8--16 LT) with a value of 2 kHz.  相似文献   

8.
Ni(II)-dien complex was prepared and characterized by X-ray diffraction. The crystal belongs to triclinic system, space group P-1, with crystallographic parametersa=0.888 13(18) nm,b=0.890 10(18) nm,c=1. 591 8(3) nm, α=77.71(3)°, β=89.12(3)°, γ=61.24(3)°,Z=2. The two dien molecules coordinate to the central Ni atom, the six nitrogen atoms form a distorted octahedron. Preliminary pharmacological tests showed this complex had antitumor activity against HepG2 and HL-60 cell linesin vitro. Foundation item, Supported by the National Natural Science Foundation of China (29972034) Biography: Li Tao (1976-), male, Ph. D candidate, research direction: ophthalmology and chemicalbiology.  相似文献   

9.
Differences in the thermodynamic functions between the liquid and crystalline states of La-based bulk metallic glasses alloys were calculated with the specific heat capacity Cp and the fusion heat ΔHf,which we measured. Fragility indexes having different thermodynamic definitions were calculated from the temperature dependence of excess entropy ΔSliq-cry. It is ambiguous for La-based glass-forming liquid to evaluate fragility from the intercepts of ΔSliq-cry-temperature curves. We found that the thermodynam...  相似文献   

10.
基于RHT模型的理论分析,选出A、N、B、M、BQ、fs/fc、Tten、D1和Ef,min 9个参数作为正交试验分析参数,研究RHT模型中参数的敏感性.运用Autodyn程序对弹丸侵彻混凝土过程进行数值分析,确定了不同参数、不同水平值下弹丸的侵彻深度.采用极差分析法对参数的敏感程度进行量化分析,得出9个参数的敏感性排序为B > Ef,min > Tten > fs/fc > N > M > D1 > BQ > A.结合3组典型数值试验损伤云图和侵彻深度的对比分析,认为参数B、Ef,min和Tten对数值模拟试验结果的影响极大,应采取可靠的技术手段准确确定其取值.   相似文献   

11.
Let dμ=ϕdν be a complex valued measure where ν is a non-negative measure and ϕ is a complex valued function which satisfiesb p + orb +a 1 condition. We prove some basic martingale inequalities such as B-G inequalities, weak (p, p) and strong (p, p) type inequalities for Banach space valued martingale with respect to complex measure μ. Supported by the National Natural Science Foundation of China Hou Youliang: born in 1956, Ph. D  相似文献   

12.
Magnetic cloud is an important interplanetary dis-turbance structure generated by the coronal mass ejections(CMEs), it has been widely investigated[1—5] since it wassuggested by Burlaga et al[1]. However, the boundary ofthe magnetic cloud has no objective definition yet. Manyobservational signatures have been used to identify thecloud boundary[6—13], as Burlaga[14] indicated, there is noconsistency among these various approaches. The problemof the BLs was not been solved because of its co…  相似文献   

13.
The fractional resonance absorption ε(0) in transmission Mossbauer spectroscopy is defined as a relative number of the absorbed γ-ray, and regarded as a measure of Mossbauer effect. The absorption linewidth Λ a , as it is usually suggested, is nearly equal to the emission linewidth, Λ s , and such an approximation leads to a extremely simplified expression ε(0), depending on neither Λ s nor Λ a . We consider the general case Λ s ≠Λ a , and obtain an exact expression for ε(0) which is given in the present paper. This expression ε(0), as a function oft a, Λ s , Λ a , is figured and discussed. Biography: Chen Yi-long (1934-), male, Professor, research interest: Mossbauer effect and its applications.  相似文献   

14.
The effect of carboxymethytl pachymaram (CMP) on the function of dendritic cells(DCs) derived from spleens of hepatitis B virus transgenic mice are studied in vitro. The phenotypes of DCs are tested by flow cytometry (FCM), cytokines measured by ELISA. The expression of DCs’ phenotypes in HBV transgenic mice are low (CD80+CD11c+:59.12±11.53 vs 9.60±4.53, p<0.01; CD80+ MHC-II+: 44.86±12.31 vs 9.80±5.72, p<0.01, normal mice vs HBV transgenic mice), the ability of DCs stimulating T lymphocytes proliferation decreases (0.37±0.11 vs 0.20±0.11, p<0.05, normal mice vs HBV transgenic mice), levels of IL-12 and IFN-γ decrease whereas the level of IL-10 increases; CMP can enhance DCs’ ability of stimulating T lymphocytes proliferation, facilitate the secretion of IL-12 and IFN-γ, inhibit the secretion of IL-10, thus up regulates DCs function. The results show a good prospective use of CMP on the treatment of chronic hepatitis B. Biography: HOU Anji (1963–), male, Ph.D. candidate, Associate professor, research direction: clinical virology.  相似文献   

15.
Here we reported the fatty-acids and their δ13C values in seep carbonates collected from Green Canyon lease block 185 (GC 185; Sample GC-F) at upper continental slope (water depth: ~540 m), and Alaminos Canyon lease block 645 (GC 645; Sample AC-E) at lower continental slope (water depth: ~2200 m) of the Gulf of Mexico. More than thirty kinds of fatty acids were detected in both samples. These fatty acids are maximized at C16. There is a clear even-over-odd carbon number predominance in carbon number range. The fatty acids are mainly composed of n-fatty acids, iso-/anteiso-fatty acids and terminally branched odd-numbered fatty acids (iso/anteiso). The low δ13C values (−39.99‰ to −32.36‰) of n-C12:0, n-C13:0, i-C14:0 and n-C14:0 suggest that they may relate to the chemosynthetic communities at seep sites. The unsaturated fatty acids n-C18:2 and C18:19 have the same δ13C values, they may originate from the Beggiatoa/Thioploca. Unlike other fatty acids, the terminally branched fatty acids (iso/anteiso) show lower δ13C values (as low as −63.95‰) suggesting a possible relationship to sulfate reducing bacteria, which is common during anaerobic oxidation of methane at seep sites.  相似文献   

16.
Carbon isotope compositions for both the carbonate shells and soft bodies (organic tissue) of living land snails collected mostly from the Loess Plateau, China have been measured. The result shows that δ 13C values range from -13.1‰ to -4.3‰ for the aragonite shell samples and from -26.8‰ to -18.0‰ for the soft body samples. Although the shells are enriched in 13C relative to the bodies averagely by 14.2(±0.8)‰, the shell δ 13Ca values are closely correlated to the body δ 13Corg values, expressed as δ 13Ca = 1.021 δ 13Corg 14.38 (R = 0.965; N = 31). This relationship indicates that δ 13Ca is primarily a function of the isotopic composition of the snail diets since previous studies have proved that the snail body is the same as their food in carbon isotope composition. In other words, carbon isotope compo-sition of the carbonate shell can be used as a proxy to estimate the dietary 13C abundance of the land snails. The data also support that the 13C enrichment of the carbonate shells results mainly from the equilibrium fractionations between the metabolic CO2, HCO3-in the hemolymph and shell aragonite, and partially from kinetic fractionations when snail shells form during their activity.  相似文献   

17.
In this paper we investigated theL 1 norm inequalities of theP square and the maximal functions of two-parameterB-valued strong martingales, which can be applied to characterizep-smoothness andq-convexity of Banach spaces. Foundation item: Supported by the National Natural Science Foundation of China Biography: YE Chen (1974-), male, Master candidate, Research interest is in stochastic processes.  相似文献   

18.
0 IntroductionZasegairerc[h1]fodre sbcirgibientde gsreavle rpaolin tmse tohnocdsert waihnicehlli ppetircm citur ovnese btyogiving the upper bound of solution. Unfortunately,this upperbound was verylarge andsometi mes beyondthe range of com-puter searching.For a particular elliptic curvey2=x3-30x+133(1)he mentioned he can find all integral points and the largestpoint is (x,y) =(5 143 326 ,±11 664 498 677) by using Mas-ser and W櫣stholz bounds on elliptic logarithms .Although recent results on…  相似文献   

19.
The influence of melt overheating on the viscosity of the melt and surface quality of the Fe_(78)Si_9B_(13) melt-spun ribbons have been studied by using oscillating vessel viscometry, X-ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy. A critical temperature Tc(about 1350℃) of the melt transformation was determined via viscosity measurements during overheating and subsequent cooling processes. The Fe_(78)Si_9B_(13) amorphous ribbons were produced through planar flow melt spinning in the temperature range of 1300–1550℃. A detailed analysis of overheating effects on the melt viscosity and surface features of the as-spun ribbons were performed to rationalize the correlation between the melt state and surface quality of the ribbons. It was found that the enhanced homogeneity of the melt can be achieved by the overheating treatment higher than the critical temperature, which in turn improves the surface quality and thickness stability of the Fe_(78)Si_9B_(13) melt-spun ribbons.  相似文献   

20.
We study the spaces Hp, Sp, Kp, ∑p and ,p of martingales with measure du=ψdυ,where ψ is a function with Clifford algebra values and satisfies bp+-condition. We proved they are equivalent and isomorphic to the corresponding spaces of martingales with real measure dυ, respectively(1≤p<∞). In the end,we give a martingale f such that f=(fn) ∞∈1K∞ but f=(E(ψ| n)fn)n≥ ∈1K∞.  相似文献   

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