Two Novel Antifungal Saponins from Tibetan Herbal Medicine Clematis tangutica

Antifungal assay-guided isolation of the ethanol extract of the aerial parts of Clematis tangutica yielded two novel triterpene saponins. Their structures were determined to be 3-O-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (1) and 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (2) on the basis of spectral data and chemical reactions.     

聚1-氨基蒽醌在二次锂电池正极材料中的应用

采用化学方法合成聚1-氨基蒽醌并用于二次锂电池正极材料,通过红外光谱、扫描电镜、粒度测试、循环伏安以及充放电测试等方法对材料的官能团结构、微观形貌、颗粒大小以及电化学性能等进行了研究与分析.实验表明,与金属锂组成二次锂电池后,聚1-氨基蒽醌达到了218.3 mAh•g－1的首次放电容量,经过25次循环后仍可保持较高的充放电效率.由于材料具有较高的能量密度且不含对环境有污染的元素S,因此是二次锂电池非常有希望的正极材料.     

珊瑚中硼的分离及其同位素组成的测定

介绍了用硼特效树脂和阴、阳混合离子交换树脂相结合进行珊瑚中硼的分离和纯化方法，满足了正热电离质谱法测定硼同位素的要求，并且对几个珊瑚样品进行了硼的分离和硼同位素组成的测定，结果满意，为研究珊瑚中的硼同位素示踪古海洋环境变化提供了可能。     

Reactive dications: the superacid-catalyzed reactions of alkynes bearing adjacent N-heterocycles or amine groups

A variety of aminoalkynes and related heterocycles are reacted in the Bronsted superacid CF(3)SO(3)H (triflic acid), and products are obtained in generally good yields (69-99%) from Friedel-Crafts-type reactions. The reactions are consistent with the formation of novel dicationic intermediates having a vinyl cationic site and an adjacent protonated N-heterocycle or ammonium cation.     

蛋氨酸合成酶催化反应研究Ⅴ：5-氨基-6-（3-羟基-4-溴丁基）尿嘧啶的合成研究

报导了5-氨基-6-（3-丁烯基）尿嘧啶、5-氨基-6-（3-羟基-4-溴丁基）尿嘧 啶的合成方法。以γ-取代的β-酮脂和O-甲基异尿硫酸盐为超始物，经6-取代尿嘧 啶（3）、6-取代-5-偶氮尿嘧啶（4）和未见文献报道的中间体6，首次合成了5-氨 基-6-（3-丁烯基）尿嘧啶（5）及5-氨基-6-（3-羟基-4-溴丁基）尿嘧啶（7）。     

A Perturbation Approach to Vector Optimization Problems: Lagrange and Fenchel–Lagrange Duality

Journal of Optimization Theory and Applications - In this paper, we study a general minimization vector problem which is expressed in terms of a perturbation mapping defined on a product of locally...     

LaSrBO4型复合氧化物的合成及其CO氧化活性研究

LaSrBO4(B=Cu、Ni、 Co、 Fe、 Mn、 Cr ) was studied with respect to their preparation, characteristics and catalytic oxidation activity by means of XRD, XPS, electric conductivity and activity evaluation. Results showed that the calcination temperature has great influence on the formation of the phases of such samples, and was associated with the radius of B ion. The greater the B ion radius, the higher the calcination temperature required for the formation of the phases. It was also found that the activity and the relative content of adsorptive oxygen and lattice oxygen on the sample surf are, the activation energy of electron conduction and the CO oxidation activity may vary with different B ions, and demonstrate a dual-peak pattern with the increase in the number of 3d electrons of the B ion.     

Hardy Spaces on the Plane and Double Fourier Transforms

We provide a direct computational proof of the known inclusion where is the product Hardy space defined for example by R. Fefferman and is the classical Hardy space used, for example, by E.M. Stein. We introduce a third space of Hardy type and analyze the interrelations among these spaces. We give simple sufficient conditions for a given function of two variables to be the double Fourier transform of a function in and respectively. In particular, we obtain a broad class of multipliers on and respectively. We also present analogous sufficient conditions in the case of double trigonometric series and, as a by-product, obtain new multipliers on and respectively.     

Optimal linear estimators of the unknown mean of a random field observed on a cross

Explicit formulas of minimum-variance linear unbiased estimators of the unknown mean are derived for homogeneous random fields with correlation functions observed on the set (a cross).Translated from Vychislitel'naya i Prikladnaya Matematika, No. 64, pp. 116–121, 1988.