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排序方式: 共有134条查询结果,搜索用时 15 毫秒
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István Kapovits József Rábai Dénes Szabó Miklós Kuti 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):435-436
The reactions of possible spiro-λ4-sulfane precursor diaryl sulfoxides with dehydrating agents have been studied resulting in the formation of cyclic anhydride, spiro-λ4-sulfane, cyclic sulfonium-ylide, lactam-sulfoxide, cyclic sulfonimide and cyclic sulfilimine type of intermediates or products. The structures of the intermediates or products depend on the functional groups attached to the aryl rings at ortho positions and on the reaction conditions applied. 相似文献
3.
Chengye Yuan Shusen Li Zhiyi Cheng 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):95-102
Abstract The mass spectra of 2-alkyl-2-oxo-1,3,2-dioxa-phosphorinane and-phosphepane showed that the ring opening was in competition with the cleavage of the P[sbnd]C bond. According to the fragmentation pathway, which was dependent on the structure of exocyclic substituents on phosphorus, the 2-alkyl-2-oxo-1,3,2-di-oxa-phosphorinanes can be classified in two categories. The main process in category A was the ring opening and/or C[sbnd]C bond cleavage. While in category B the cleavage of P[sbnd]C bond was predominant. However, for 2-alkyl-2-oxo-1,3,2-dioxa-phosphepane. no matter how the structure of 2-alkyl group was, the ring opening was a dominant process. 相似文献
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本文将概述窄线SeyfertⅠ型星系 (包括具有类似性质但光度较大的类星体 )的主要观测特征、物理内涵及其理论解释和在活动星系核内部结构上的反映。窄线SeyfertⅠ型星系 (NLS1 ,以后NLS1都认为包括NLSI星系和NLS1类星体 )具有窄的允许线Hβ,它兼有Sy1和Sy2的某些特征。它具有强的FeⅡ光学线和弱的 [OⅢ ]λ5 0 0 7禁线 ,这明显不同于Sy2。在观测相关量的主成分统计分析中表明NLS1是活动星系核第一主向量表现为极端的一类。这包括 :( 1 )HβFWHM取极小 ;( 2 )FeⅡλ45 70 /Hβ 取极大 ;( 3)SⅢ ]λ1 892 /CⅢ ]λ1 90 9取极大 ,亦一定范围内宽线区电子密度取大值 ;( 4 )CⅣλ1 5 4 9线中心蓝移取极大 ;( 5 )高光度NLS1的软X射线光子数谱指数Γx 取极大 ;( 6)X射线相对流量变化方差最大等。基于以上观测结构和相应统计规律 (观测量与HβFWHM的关系 ) ,解释NLS1现象最佳的模型是高相对吸积率L/LEdd模型。NLS1比之典型宽线活动星系核具有较低的中心黑洞质量MBH。进一步 ,还发现这一模型是活动星系核主... 相似文献
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对N(2,2,0)代数(∈,∈∨q_((λ,μ)))-模糊关联理想若干性质进行了详细的研究.首先,运用点态化的方法证明了(∈,∈∨q_((λ,μ)))-模糊关联理想的同态像与同态原像的基本性质;其次,研究了(∈,∈∨q_((λ,μ)))-模糊关联理想的直积;最后,讨论了(∈,∈∨q_((λ,μ)))-模糊关联理想的直积的投影子集. 相似文献
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Let ? ∈ L~2(S~(n-1)) be homogeneous function of degree zero and b be BMO functions. In this paper, we obtain some boundedness of the Littlewood-Paley Operators and their higher-order commutators on Herz spaces with variable exponent. 相似文献
7.
A series of 2-(arylimino)-3-(hydroxyimino)butanes 3a–g, easily accessed by the condensation of variously substituted anilines 1a–g with biacetyl monoxime 2, were efficiently cyclized to afford 2,3-dimethylquinoxaline-1-oxides 4a–g using bis(acetoxy)phenyl-λ 3-iodane as an oxidant. This methodology utilizes a commercially available and environmental benign oxidant to achieve the title compounds in excellent yields under mild conditions.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
8.
Some generalizations of the Apostol-Genocchi polynomials and the Stirling numbers of the second kind
Qiu-Ming Luo 《Applied mathematics and computation》2011,217(12):5702-5728
Recently, the authors introduced some generalizations of the Apostol-Bernoulli polynomials and the Apostol-Euler polynomials (see [Q.-M. Luo, H.M. Srivastava, J. Math. Anal. Appl. 308 (2005) 290-302] and [Q.-M. Luo, Taiwanese J. Math. 10 (2006) 917-925]). The main object of this paper is to investigate an analogous generalization of the Genocchi polynomials of higher order, that is, the so-called Apostol-Genocchi polynomials of higher order. For these generalized Apostol-Genocchi polynomials, we establish several elementary properties, provide some explicit relationships with the Apostol-Bernoulli polynomials and the Apostol-Euler polynomials, and derive various explicit series representations in terms of the Gaussian hypergeometric function and the Hurwitz (or generalized) zeta function. We also deduce their special cases and applications which are shown here to lead to the corresponding results for the Genocchi and Euler polynomials of higher order. By introducing an analogue of the Stirling numbers of the second kind, that is, the so-called λ-Stirling numbers of the second kind, we derive some basic properties and formulas and consider some interesting applications to the family of the Apostol type polynomials. Furthermore, we also correct an error in a previous paper [Q.-M. Luo, H.M. Srivastava, Comput. Math. Appl. 51 (2006) 631-642] and pose two open problems on the subject of our investigation. 相似文献
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10.
Pei-Kee Lin 《Journal of Mathematical Analysis and Applications》2005,312(1):138-147
Let (X,F,μ) be a complete probability space, B a sub-σ-algebra, and Φ the probabilistic conditional expectation operator determined by B. Let K be the Banach lattice {f∈L1(X,F,μ):‖Φ(|f|)‖∞<∞} with the norm ‖f‖=‖Φ(|f|)‖∞. We prove the following theorems:
- (1)
- The closed unit ball of K contains an extreme point if and only if there is a localizing set E for B such that supp(Φ(χE))=X.
- (2)
- Suppose that there is n∈N such that f?nΦ(f) for all positive f in L∞(X,F,μ). Then K has the uniformly λ-property and every element f in the complex K with is a convex combination of at most 2n extreme points in the closed unit ball of K.