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1.
A labeling/of a graph G is a bijection from its edge set E(G) to the set {1,2,…,|E(G)|},which is antimagic if for any distinct vertices x anAy,the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y.A graph G is antimagic if G has an f which is antimagic.Hartsfield and Ringel conjectured in 1990 that every connected graph other than K_2 is antimagic.In this paper,we show that if G_1 is an m-vertex graph with maximum degree at most 6r+l,and G_2 is an n-vertex(2r)-regular graph(m≥n≥3),then the join graph G_1 v G_2 is antimagic.  相似文献   

2.
In this work, we study the quasilinear initial-boundary value problem $\sum\limits_{i, j = 1}^m {X_i^ * A_{i j} (x, t, u)X _j u} + \sum\limits_{j = 1}^m {B_j (x, t, u)X _j u + C} (x, t, u) = 0$ , in ]0,TΩ;u| t=0 =φ, onΩ;u=ψ, on [0,T, whereX={X 1, ...,X m } is a system of real smooth vector fields which is defined on an open domainM of R n , and satisfies the Hörmander's condition, Ω?M. Assume that ?Ω is non characteristic for the systemX 1,...,X m . Under some hypothesis for the boundary of domain and the elliptic structure condition for nonlinear coefficientsA ij ,B j ,C, (i, j=1, ...,m), we have proved that the existence and regularity of solution for aboveinitial-boudary value problems.  相似文献   

3.
The wide compatibility gene, S 5 n , can overcome embryo sac sterility between indica and japonica subspecies of rice. Therefore, it is very important to characterize the features of the S 5 n sequence to reveal the origin and evolution of S 5 n . In this paper, 26 cultivated rice haplotypes and 22 wild rice accessions harboring S 5 n were used to sequence S 5 n . The results showed that 15 genotypes among the 48 materials were fully consistent with control cultivar 02428 (CK). The other 33 accessions had different degrees of variation in the S 5 n sequence. Variations in the coding region mainly occurred in the second exon and eight materials showed a 10-bp deletion at 1710?C1719 bp, including wild (O. nivara) and cultivated rice, such as IRW501 and Yuetai B. S 5 n sequences were not biased and evolved neutrally. The 48 materials could be divided into 4 categories using a phylogenetic tree of the amino acid sequences. Most of the wild rice clustered together, and the cultivated rice clustered into another group. Eight cultivated rice and O. nivara (wild rice) clustered in another group, which were found to lack 10 consecutive bases in exon 2. Eight rice varieties with high numbers of differences in their S 5 n coding regions were crossed with testers (typically indica and japonica) to produced test cross F1 populations. The F1s were examined for their ability to overcome indica-japonica hybrid sterility. The result showed that the embryo sac fertility of S 5 n -containing hybrids increased significantly compared with control hybrids, but there were no differences among the materials with divergent sequences, indirectly proving that S 5 n is a non-functional gene.  相似文献   

4.
In this paper, we establish an inequality for the volumes of K and its radial p-th mean body R_pK by L_p-dual mixed volume. Further, the Shephard-type problem and a monotonitic inequality of R_pK are shown when p>0 .  相似文献   

5.
The distribution of a CP-asymmetric quantityA in the decay channelJ/ψπ + π ? π 0 is investigated. This dimensionless quantityA is constructed from the momenta of the π-meson final states, namely A=P x π + P y π ? -P x π ? P y π ?, whereP h,P x h andP y h are the module of the momentum of a hadron h, the x- and y-components of that momentum respectively, theJ/ψ particle is produced by e+ e? collision, and the direction of the momentum of e+ is taken to be the positive direction ofz axis. There would exists the violation under the combined transformation of charge conjugation and space reflection (CP violation) when the average ofA among a lot of events, 〈A〉, be examined to be nonzero clearly from data. In this way, 748 events are selected from the BES experimental data, and analyzed. The corresponding averageA-value is measured to be 〈A〉 = 0.010 39 ± 0.014 61 ± 0.015 2. Further, some discussion of our result, the size of the data sample being need for further attempt and a possible perspective are given.  相似文献   

6.
Undercooled Fe75Ni25 melts were phase-seeded by a high purity iron. It was found that above a critical undercooling,△Tc = 135 K, a metastable δ phase (b.c.c) solidifies from the iron-seeded melts instead of a thermodynamically stable γ phase (f.c.c). While undercooling of the melt (△T ) is below △Tc, solidification of the γ phase prevails in the iron-seeded melts. For the undercooled melts subjected to spontaneous nucleation, the γ phase always solidifies. After solidification, the as-solidified γ phase transforms completely to martensite; whereas the as-solidified metastable δ phase partially transforms to the γ phase, and then to martensite. The untransformed δ phase retains as a -ferrite particles in the microstructures. Based on the classical nucleation theory, catalytic nucleation of the metastable δ phase in the phase-seeded undercooledFe75Ni25 melts was analyzed. It was quantitatively demonstrated that when△T>△Tc, the formation of the δ phase can be ascribed to a better catalytic effect of the iron on its nucleation than that on the nucleation of the γphase.  相似文献   

7.
Specimens of Pb1?1.5xLax(Zr0.53Ti0.47)1?y?zFeyNbzO3(x = 0, 0.004, 0.008, 0.012, and 0.016, y = z = 0.01) (PZTFN) ceramics were synthesized by a semi-wet route. In the present study, the effect of La doping was investigated on the structural, microstructural, dielectric, piezoelectric, and ferroelectric properties of the ceramics. The results show that, the tetragonal (space group P4mm) and rhombohedral (space group R3c) phases are observed to coexist in the sample at x = 0.012. Microstructural investigations of all the samples reveal that La doping inhibits grain growth. Doping of La into PZTFN improves the dielectric, ferroelectric, and piezoelectric properties of the ceramics. The hysteresis loops of all specimens exhibit nonlinear behavior. The dielectric, piezoelectric and ferroelectric properties show a maximum response at x ≥ 0.012, which corresponds to the morphotropic phase boundary (MPB).  相似文献   

8.
High-surface-area and well-ordered mesopor- ous Fe-incorporated SBA-15 (xFe-SBA-15) and SBA-15- supported FeOx (yFeOx/SBA-15) with the Fe surface den- sity between 0.09 to 1.11 Fe-atom/nm2 have been prepared using the one-step synthesis and incipient wetness impregnation methods, respectively. Physicochemical properties of these materials were characterized by means of numerous techniques, and their catalytic activities for the combustion of toluene were evaluated. It is found that the xFe-SBA-15 and yFeOx/SBA-15 samples possessed rod- or chain-like morphologies. The Fe species were of high dispersion when the Fe surface density was lower than 0.76 Fe-atom/nm2 in xFe-SBA-15 and 0.64 Fe-atom/nm2 in yFeOx/SBA-15. At a similar Fe surface density and space velocity, the xFe-SBA-15 catalysts showed better activity than the yFeOJSBA-15 catalysts, in which the xFe-SBA- 15 catalyst with Fe surface density 0.59 Fe-atom/nm2 performed the best. It is concluded that the good perfor- mance of the xFe-SBA-15 sample with Fe surface density 0.59 Fe-atom/nm2 was associated with its large surface area, high Fe species dispersion, and good low-temperature reducibility.  相似文献   

9.
根据第四统计力学——JRG群子统计理论,首次提出了形成原子核结构的四项原理及相应的原子核周期律。这四项原理为:一是原子核有群子结构单元;二是形成原子核时群子通过热核聚合反应过程使核素结构有严格的排列顺序;三是原子核内群子结构间有动态共振作用;四是偶数群子稳定,而非偶数群子是引起总角动量和β+-衰变的根源。基于上述四项原理,提出了核群子结构基本单元有(PB),(PB2),(P2B3),并随着质子数Z的增加,核群子结构由(PB)k过渡到(PB)k(P2B3)l;由(PB)n(PB2)m过渡到(P2B3)s(PB2)t。从而导出了k(-t)=2n(s)-Z,k(-t)=Z-2l(m)的关系式。基于此,可以画出等腰三角形原子核群子周期律。还发现,不管A,N,Z如何变化,有下列严格关系式:Z/N=(n+m)/(n+2m)或Z/N=(k+l)/(k+3l)并且Z=n+l。此公式高度地反映了所有原子核内质子和中子分布的整数规律。还可以通过等腰三角形周期律得知:k,l,m,n,s,t均与核素群子(PB),(PB2), (P2B3),(P3B4)的2,3,5,7整数倍有关。  相似文献   

10.
11.
LetA bem byn matrix,M andN be positive definite matrices of orderm andn respectively. This paper presents an efficient method for computing (M?N) singular value decomposition ((M?N) SVD) ofA on a cube connected single instruction stream-multiple data stream (SIMD) parallel computer. This method is based on a one-sided orthogonalization algorithm due to Hestenes. On the cube connected SIMD parallel computer witho(n) processors, the (M?N)SVD of a matrixA requires a computation time ofo(m 3logm/n).  相似文献   

12.
化合物5,5’-偶氮四唑钠(2)在稀盐酸中分解得到5-肼基四唑盐酸盐(3),5-肼基四唑盐酸盐与氢氧化钠中和后除去产物中的NaCl,在甲醇中重结晶得到5,5’-偶氮四唑-5-氮氧化物钠五水合物(4),采用MS,元素分析等对这些化合物进行表征. 用X射线单晶衍射法测定获得了化合物 3 和4的晶体数据. 化合物3属于单斜晶系,P2(1)/n空间群,其晶胞参数a=0.438(2)nm,b=2.395 6(2)nm,c=0.493 6(2)nm,Z=4,V=0.546(4)nm3,Dc=1.659 g/cm3,F(000)=280;化合物 4属于三单斜晶系,P-1空间群,其晶胞参数a=0.715 81(19) nm,b=0.766 3(2)nm,c=1.193 3(4) nm,Z=2,V=0.602 7(3) nm3,Dc=1.742 g/cm3,F(000)=324.   相似文献   

13.
Magnetic Co1-xNixFe2O4 nanoparticles (NPs) were successfully synthesized via a solvothermal method using ethylene glycol as solvent.The samples were characterized by X-ray diffraction (XRD),field emiss...  相似文献   

14.
最小Q-特征值为给定整数的一类图   总被引:1,自引:1,他引:0  
研究了基于二部图H构造的一类图的最小无符号拉普拉斯特征值,即最小Q-特征值,得到了它的最小Q-特征值的可达上界为1.给出了最小Q-特征值为1的2个必要条件,并构造了最小Q-特征值为1的一类图.另外,给出了利用H∨K1的最小Q-特征值来判断简单图H没有完美匹配的方法,以及图G增加边后最小Q-特征值保持不变的1个充分条件.最后,构造了最小Q-特征值为任意给定的正整数t的一类图.  相似文献   

15.
A modified criterion,β',defined as T_g/T_x-T_g/(T_l·η))(T_g,T_x,T_l andηdenote the glass transition temperature,the onset of crystallization temperature,the liquidus temperature and constant coefficient,respectively),has been proposed for assessing the glass-forming ability(GFA) of bulk metallic glasses(BMGs).A survey of the readily available experimental data associated with the thermal analysis of various BMG alloys demonstrates that the newβ' criterion exhibits much better correlation with the GFA tha...  相似文献   

16.
The relative changes between shear and compressional velocities (RSP = ∂ ln VS/∂ ln VP), bulk sound and shear velocities (RCS = ∂ ln VC/∂ ln VS), and density versus shear wave velocity (RρS = ∂ ln ρ/∂ ln VS) in response to thermal and chemical variations were investigated for the pyrolitic lower mantle. For heterogeneities with thermal origins, RSP increases from 1.7 to 2.0 together with RρS decreasing from 0.4 to 0.2 and RCS = ∼0.27 from the top to the bottom of the lower mantle. In comparison, chemical variations (bulk iron or silica contents) are characterized by RSP < 1.5 and RCS > 0.5 at lower mantle depths. Negative values of RρS and RCS are indicative of chemical anomalies in the lower mantle, but a combination of thermal and chemical heterogeneities may be required to produce velocity and density anomalies at the magnitudes observed in seismic data. Further refinement of these characteristics requires data on the higher order pressure and temperature derivatives of the elastic moduli of the constituent phases.  相似文献   

17.
以电性距离矢量Mt表征165种非离子性有机物(NOC)的分子结构.利用多元回归方法建立了122种NOC的生物富集因子(lg BCF)与32个Mt的数学模型,其相关系数R为0.976.经逐步回归建立最佳四变量(M15,M17,M36,M91)模型,其R为0.960;并以Jackknife法检验,其LOO交互检验系数(q2)为0.915.这4个Mt参数揭示了影响NOC生物富集因子的主要因素,结果表明该模型具有良好的估算能力与鲁棒性.以111个NOC为训练集的生物富集模型作用于11个NOC的检验集,显示出良好的预测能力.  相似文献   

18.
The Pb-17wt% Sb alloy was directionally solidified under two solidification conditions: with different temperature gradients (G=0.93–3.67 K/mm) at a constant growth rate (V=17.50 μm/s) and with different growth rates (V=8.3–497 μm/s) at a constant temperature gradient (G=3.67 K/mm) in a Bridgman furnace. Microstructure parameters, such as primary dendrite arm spacing (λ1), secondary dendrite arm spacing (λ2), and dendrite tip radius (R), were measured. The microhardness (Hv) and ultimate tensile strength (σ) of the directional solidification samples were also measured. The influences of solidification and microstructure parameters on Hv and σ were investigated. The results obtained in this work were compared with similar experimental researches in literatures. It is shown that the Hv and σ values increase with the increase of G and V, but decrease with the increase of λ1, λ2, and R.  相似文献   

19.
Human β-definsin-2 (hBD-2) is mainly induced by bacterial factors and pro-inflammation mediators in epithelial cells. As the major cause of community-acquired pneumonia, whether Streptococcus pneumoniae (S. pneu-moniae) stimulation induces hBD-2 expression in airway epithelial cells is elusive. In this study, we found that S. pneumoniae stimulation induced hBD-2 expression in a time-and concentration-dependent manner in primary human airway epithelial cells. To further reveal the mechanism of S. pneumoniae inducing hBD-2, we found that S. pneumoniae stimulation activated NF-κB signaling pathway. Specific NF-κB inhibitor, PDTC, could reverse the induction of hBD-2 by S. pneumoniae. We also found that cellular inner Ca^2+ signaling is involved in the S. pneumoniae-induced hBD-2. Taken together, our find-ings indicated that S. pneumoniae can stimulate the expression of hBD-2 in airway epithelial cells and NF-κB and inositol triphosphate-dependent intracellular calcium release is involved in this induction.  相似文献   

20.
In this paper,the definition of the general L p-mixed projection bodies is introduced,and the general L p-projection bodies given by Ludwig is a special case for the general L p-mixed projection bodies.Then the Petty projection inequality for the general L p-mixed projection bodies is shown.Moreover,the monotonicity for the general L p-mixed projection bodies is obtained.  相似文献   

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