新型稀土电子输运材料Tb(AcA)3·phen

Kido等人在文献[1]中报导,在研究有机电致发光(OEL)器件时发现,斓系化合物不能很好地传输载流子.但是,我们在实验中却现Tb(AcA)3phen·不仅是一种很好的OEL发射材料.而且具有很强的电子输运能力.     

Transversely polarized parton densities,their evolution and their measurement

The transverse spin asymmetry of a quark in a baryon and the linear polarization of a gluon in a vector meson are studied from thet-channel point of view. Using the Altarelli-Parisi approach, they are shown to obey independent evolution equations and to decrease with increasingQ ². We investigate the possibility to measure them at leading twist, to leading order in α and α_s and without analyzing the final polarizations. This requires simultaneous polarization of the beam and the target; the observable effect is in the azimuthal distribution of the highP _T particle or jet. Assuming a simple (quark+scalar diquark) model for the baryon, a large asymmetry is expected inp \(\bar p\) Drell-Yan collisions, a smaller one in highP _T pp collisions, from the interference term in the scattering of two identical quarks.     

Circles through two points that always enclose many points

This paper proves that any set of n points in the plane contains two points such that any circle through those two points encloses at least points of the set. The main ingredients used in the proof of this result are edge counting formulas for k-order Voronoi diagrams and a lower bound on the minimum number of semispaces of size at most k.Work on this paper by the first author has been supported by Amoco Fnd. Fac. Dev. Comput. Sci. 1-6-44862 and by the National Science Foundation under Grant CCR-8714565, by the second author has been partially supported by the Digital Equipment Corporation, by the fourth author has been partially supported by the Office of Naval Research under Grant N00014-86K-0416.     

An experimental investigation of high permittivity dielectric resonators for millimeter-wave microstrip components

This paper proposes a new type of high permittivity whispering gallery mode cylindrical dielectric resonators with a geometry which is very suitable for use in microstrip type integrated circuits. These oversized resonators, together with high Q factors and ease of fabrication, are potentially interesting for millimeter wave integrated filters and oscillators. In this paper, we report an experimental investigation of such resonators carried out in Ka band (26.5–40 GHz). Measured results including resonant frequencies and loaded quality factors will be presented. Application to millimeter wave filters will also be demonstrated.     

钌催化二氧化碳加氢合成甲酸的研究

钌催化二氧化碳加氢合成甲酸的研究张俊忠，李忠，王辉，王常有（太原工业大学煤化所Ｃ１室，太原０３００２４）关键词ＣＯ_２催化加氢，甲酸合成，钌络合催化剂１．前言由于ＣＯ２对环境、气候和生态等方面带来愈加恶劣的影响以及碳资源的日益短缺，近年来对ＣＯ２开发?..     

后处理温度对ZrO2气凝胶超细粉织构和结构的影响

运用神效儿宝治疗小儿厌食症２１０例，总有效率为９５．２％，显效率为６２．４％。该药使用、携带方便、见效快，疗效短，无毒副作用。实验证明，该药能显著提高胃蛋白酶含量，减慢肠管推进性运动，提高动物耐疲劳、耐缺氧能力，提高巨噬细胞吞噬率及血清补Ｃ３含量，且无毒副。作用     

大孔吸附树脂负载氢氧化锰作催化剂空气氧化水中硫化物的研究

采用ＮＫＡ２型大孔吸附树脂负载氢氧化锰作催化剂，研究模拟水样中硫化物的空气氧化过程和影响因素，并对煤气和焦化工业含硫废水进行氧化试验．结果表明，在ｐＨ９～１１和不低于３０℃的条件下，浓度６３０～３８００ｍｇ／ｌ的Ｓ２－可在１～３小时内达到９９％的氧化率，树脂负载催化剂可重复使用．     

Sonochemical Degradation of Polychlorinated Biphenyls in Aqueous Solution

Ultrasonic waves in a liquid induce the formation of cavitation bubbles. Submitted to an oscillating pressure field, cavities filled with vapor and dissolved gas pulsate, grow and implode violently when they reach a critical resonant size. According to the 慼ot spot?theory, extremely high temperature and pressure are produced during the collapse of cavitation bubbles1. Under these extreme conditions, the molecules vaporized in the bubbles as well as in the surrounding condensed layer could …     

Electronic properties of polyoxometalates: a DFT study of alpha/beta-[XM(12)O(40)](n-) relative stability (M=W, Mo and X a main group element)

Keggin heteropolyanions [XM(12)O(40)](n-) have various isomeric structures, alpha and beta being the most common. Conventionally, the alpha structure appears to be the most stable, but calculations carried out at the DFT level for X = P(V), Si(IV), Al(III), As(V), Ge(IV), and Ga(III) and M = W(VI) and Mo(VI) show that this stability depends on several factors, particularly on the nature of the heteroatom (X) and the total charge of the cluster. In this paper, we apply the clathrate model to the Keggin molecule to carry out a fragment-interaction study to elucidate when and why the traditional relative stability of various isomers can be inverted. The fully oxidized anions that have inverted the traditional stability trend in this series are [AlW(12)O(40)](5-) and [GaW(12)O(40)](5-), both of which contain a third-group heteroatom and an overall charge of -5. beta-isomers are always more easily reduced than alpha-isomers. This experimental observation suggests that reduction favors the stability of beta-isomers and one of the most important results of this study is that the alpha/beta inversion is achieved in most cases after the second reduction. The alpha- and beta-isomers may have different properties because the energy of the LUMO, a symmetry-adapted d(xy)-metal orbital, is different.