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991.
Ricardo Abreu-Blaya Juan Bory-Reyes Fred Brackx Hennie De Schepper Frank Sommen 《数学学报(英文版)》2012,28(11):2289-2300
A Hilbert transform for H?lder continuous circulant (2 × 2) matrix functions, on the d-summable (or fractal) boundary Γ of a Jordan domain Ω in ?2n , has recently been introduced within the framework of Hermitean Clifford analysis. The main goal of the present paper is to estimate the H?lder norm of this Hermitean Hilbert transform. The expression for the upper bound of this norm is given in terms of the H?lder exponents, the diameter of Γ and a specific d-sum (d > d) of the Whitney decomposition of Ω. The result is shown to include the case of a more standard Hilbert transform for domains with left Ahlfors-David regular boundary. 相似文献
992.
A set W of the vertices of a connected graph G is called a resolving set for G if for every two distinct vertices u, v ∈ V (G) there is a vertex w ∈ W such that d(u, w) ≠ d(v, w). A resolving set of minimum cardinality is called a metric basis for G and the number of vertices in a metric basis is called the metric dimension of G, denoted by dim(G). For a vertex u of G and a subset S of V (G), the distance between u and S is the number min s∈S d(u, s). A k-partition Π = {S 1 , S 2 , . . . , S k } of V (G) is called a resolving partition if for every two distinct vertices u, v ∈ V (G) there is a set S i in Π such that d(u, Si )≠ d(v, Si ). The minimum k for which there is a resolving k-partition of V (G) is called the partition dimension of G, denoted by pd(G). The circulant graph is a graph with vertex set Zn , an additive group of integers modulo n, and two vertices labeled i and j adjacent if and only if i-j (mod n) ∈ C , where CZn has the property that C =-C and 0 ■ C. The circulant graph is denoted by Xn, Δ where Δ = |C|. In this paper, we study the metric dimension of a family of circulant graphs Xn, 3 with connection set C = {1, n/2 , n-1} and prove that dim(Xn, 3 ) is independent of choice of n by showing that dim(Xn, 3 ) ={3 for all n ≡ 0 (mod 4), 4 for all n ≡ 2 (mod 4). We also study the partition dimension of a family of circulant graphs Xn,4 with connection set C = {±1, ±2} and prove that pd(Xn, 4 ) is independent of choice of n and show that pd(X5,4 ) = 5 and pd(Xn,4 ) ={3 for all odd n ≥ 9, 4 for all even n ≥ 6 and n = 7. 相似文献
993.
994.
利用从现场取得的原状土样,通过室内动三轴试验对循环荷载作用下的变形、孔压和强度特性进行研究。试验研究主要考虑了周围固结压力、循环剪切应力比、荷载频率和循环次数等因素的影响。研究表明,在循环荷载作用下,孔隙水压力和轴向应变均是一个波动上升的过程。当循环应力比增大时,动孔隙水压力变化幅值显著增加,而残余孔压也较大。同时,孔隙水压力值也随着周围压力的增大而明显增大。当作用荷载频率比较大时,需要更多的循环次数才能达到小频率作用荷载能达到的孔隙水压力值。但是,随着循环荷载作用次数的增加,频率对孔隙水压力的影响有减小的趋势。 相似文献
995.
孔周弹塑性变形与疲劳循环次数的相关性 总被引:2,自引:1,他引:1
应用白光散斑相关技术研究了孔周弹塑性变形与疲劳循环次数的相关性,以便探索疲劳寿命的预测方法.疲劳实验在单边带缺口的拉伸板状试件上进行,试件由GH4169材料制成,试件表面上喷涂了白光散斑图.疲劳加载采用0→Pmax→0的循环加载方式,加载波形为正弦波,加载频率为10Hz.实验中,按一定的疲劳循环周次在零载及最大载荷两种状态下停机、采图.应用数字图像相关技术求出孔周附近的残余位移场,并应用逐点最小二乘法求出应变场.实验中获得了一些对于疲劳寿命研究很有意义的结果. 相似文献
996.
从原子能级演化的速率方程出发,以镱(Yb)原子为研究对象,通过求解Yb原子在各能级演化的动力学行为,得到了Yb原子体系的冷却循环跃迁的存在能级,即单态跃迁~1s_0→~1p_1和单态到三态跃迁~1s_0→~3p_1,该结果与目前的实验完全符合.在不考虑相关碰撞的情况下,该方法从理论上分析了目前研究比较成熟的Yb原子,从而试图寻找一种能够方便找到复杂原子能级结构中冷却循环跃迁的普适方法并且用于指导实验,推动超冷原子物理研究的进程. 相似文献
997.
998.
将金属钴离子引入磷酸铝分子筛APO-5制得CoAPO-5分子筛,再把N,N-双水杨醛缩乙二胺(SALEN)希夫碱通过扩散进入CoAPO-5分子筛孔道并与其中的钴离子配位,形成了CoSALEN配合物,构成CoSALEN/APO-5复合材料.应用物理吸附法,以聚苯乙烯(PS)作粘结剂,将CoSALEN/APO-5涂敷在玻碳电极表面制成修饰电极PS/CoSALEN/APO-5/GCE.循环伏安法(CV)、计时电流法(CA)研究了该修饰电极在不同pH电解质溶液中的电化学行为以及对分子氧的催化还原作用.结果表明,制备的修饰电极能有效地催化分子氧的四电子还原,即氧气被电催化还原为水,据此提出可能的氧还原机理. 相似文献
999.
以壳聚糖(CS)为多壁碳纳米管(MWNTs)的分散介质, 通过MWNTs/CS膜上大量氨基静电吸附纳米金粒子(nanoAu), 使玻碳电极(GCE)表面形成稳定的nanoAu-MWNTs-CS-GCE修饰层, 并采用电化学方法初步研究了该修饰电极的性能. 探讨了吲哚乙酸(IAA)在该修饰电极上的电化学行为, 结果表明, 在5~200 μmol/L浓度范围内以及0.78 V电位条件下, 以循环伏安法(CV)测得的氧化峰电流变化值与c(IAA)呈良好的线性关系, 其回归方程为y=2.34×10-4+0.14x, 检出限为8.33×10-6 mol/L, 相关系数为0.9997. 相似文献
1000.
While circulating fluidized bed (CFB) reactor has many advantages over the more conventional turbulent fluidized bed (TFB) reactor, it does at least have one significant shortcoming-the rather dilute solids volume concentration in CFB reactor gives rise to less ideal reaction intensity. On the other hand, while having higher reaction intensity, TFB reactor has one fatal drawback of particle back-mixing, making it not suitable for certain reactions such as catalytic reaction where the catalyst requires frequent regeneration. This paper describes some key issues in the development of a circulating turbulent fluidized bed (CTFB) reactor that combines the advantages of both TFB and CFB, that is, to have the high reaction intensity as in TFB but and also to have a suppressed solids back-mixing as in CFB due to a continuous net upflow of solids flux through the bed. Experimental results show enough evidence to suggest that a new fluidization regime is formed, the characteristics of which appears to be distinct from those observed in a regular TFB and from those in either the bottom or the upper sections of regular CFB and/or high-density CFB (HDCFB). Fundamentally, the difference is that particle-particle interaction (collision) dominates the motion of particles in CTFB and TFB, while gas-particle interaction (drag force) is the key element that determines the two phase flow in CFB including HDCFB. 相似文献