用CCD分析光源的辐射光谱

本文介绍了利用光电图象技术对光源光谱进行分析的工作。利用ＣＣＤ线阵器件和计算机，我们获得了黑体、灰体及单色光源的光谱特性以及有关数据。     

带利息力和干扰的批量索赔一般到达风险模型

本文在经典风险模型的基础上,将索赔到达过程推广为更新过程,索赔可以批量到达,且带有常数利息力和Brown运动干扰项,得到一个新的风险模型,运用Markov骨架过程的方法,得出盈余过程的瞬时分布和生存概率.     

SMAP／INDI／1单重休假随机服务系统的MSP方法

本文借助于马尔可夫骨架过程(MSP)方法研究了SMAP/INID/1单重休假随机服务系统的队长及等待时间等指标的瞬时分布.     

Five new eremophilane derivatives from Ligularia sagitta

Ligulasagitins A-E (1-5), five new eremophilane-derived metabolites possibly formed via a Diels-Alder reaction in the biosynthetic process, were isolated from Ligularia sagitta Maxim. Among them 1 and 2 possess a novel C19 skeleton, 4 and 5 are two novel dimeric eremophilane type derivatives. Their structures were determined by extensive spectroscopic analysis and the structure of 2 was also confirmed by a single-crystal X-ray diffraction analysis. Furthermore, 4 and 5 showed weak cytotoxic activity against HL-60 (human promyelocytic leukemia) cells.     

Domino allylation and cyclization of ortho-alkynylbenzaldehydes with allyltrimethylsilane catalyzed by Pd(II)-Cu(II) bimetallic systems

The reaction of ortho-alkynylated benzaldehydes 1 with allyltrimethylsilane under the Pd(OAc)₂-CuCl₂ catalyst system gave the isochromene derivatives 2 together with the chlorinated products 3. When the reaction was conducted in the presence of half equiv of H₂O, the formation of 3 was suppressed and 2 was obtained in good to high yields. When the reaction of 1a was carried out with trimethylsilylcyanide instead of allylsilane, the cyano group-substituted isochromene 9 was obtained in 94% yield.     

Spectra of computable models for Ehrenfeucht theories

We construct an example of a theory with a finite (greater than one) number of isomorphism types of countable models such that its prime and saturated models have computable presentations and there exists a model which lacks in such. Supported by the Council for Grants (under RF President) and State Aid of Fundamental Science Schools via project NSh-4413.2006.1. __________ Translated from Algebra i Logika, Vol. 46, No. 3, pp. 275–289, May–June, 2007.     

Synthetic study of (+)-anthramycin using ring-closing enyne metathesis and cross-metathesis

Synthesis of (+)-anthramycin was examined. A pyrrolobenzodiazepine skeleton could be synthesized by reductive cyclization of pyrrolidine derivative, which was obtained by enyne metathesis. The conjugated enamide ester part of (+)-anthramycin derivative was constructed by cross-metathesis.     

GI／G／1单重休假随机服务系统的马氏骨架方法

文献[1]引入一类具有广泛应用前景的随机过程-Markov骨架过程。借助Markov骨架过程的方法研究GI/G/1单重休假服务系统队长，及t时刻到达顾客等待时间的瞬时概率分布。     

The braid groups of the projective plane and the Fadell–Neuwirth short exact sequence

We study the pure braid groups of the real projective plane , and in particular the possible splitting of the Fadell–Neuwirth short exact sequence , where n ≥ 2 and m ≥ 1, and p _* is the homomorphism which corresponds geometrically to forgetting the last m strings. This problem is equivalent to that of the existence of a section for the associated fibration of configuration spaces. Van Buskirk proved (1966, Trans. Am. Math. Soc., 122:81–97) that p and p _* admit a section if n = 2 and m = 1. Our main result in this paper is to prove that there is no section if n ≥ 3. As a corollary, it follows that n = 2 and m = 1 are the only values for which a section exists. As part of the proof, we derive a presentation of : this appears to be the first time that such a presentation has been given in the literature.      

Symplectic spread-based generalized Kerdock codes

Kerdock codes (Kerdock, Inform Control 20:182–187, 1972) are a well-known family of non-linear binary codes with good parameters admitting a linear presentation in terms of codes over the ring (see Nechaev, Diskret Mat 1:123–139, 1989; Hammons et al., IEEE Trans Inform Theory 40:301–319, 1994). These codes have been generalized in different directions: in Calderbank et al. (Proc Lond Math Soc 75:436–480, 1997) a symplectic construction of non-linear binary codes with the same parameters of the Kerdock codes has been given. Such codes are not necessarily equivalent. On the other hand, in Kuzmin and Nechaev (Russ Math Surv 49(5), 1994) the authors give a family of non-linear codes over the finite field F of q = 2 ^l elements, all of them admitting a linear presentation over the Galois Ring R of cardinality q ² and characteristic 2². The aim of this article is to merge both approaches, obtaining in this way new families of non-linear codes over F that can be presented as linear codes over the Galois Ring R. The construction uses symplectic spreads.