Two Novel Myrinsol Diterpenes from Euphorbia prolifera

Two novel diterpenes,Euphorprolitherin A(1) and Euphorprolitherin B(2), were isolated from the roots of Euphorbia prolifera. Their structures were elucidated on the basis of spectroscopic methods.     

手性双氨基醇-Et2Zn催化的不对称直接羟醛缩合反应

以1,3-二溴丙酮和(2'S)-(二苯基羟甲基)-四氢吡咯为原料,合成了两种新型手性氨基醇1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]丙酮(3)和1,3-双[(2'S)-(二苯基羟甲基)-1-四氢吡咯基]-2-丙醇(4),总产率分别为39%和35%.手性双氨基醇3-/4-Et2Zn可催化未修饰醛、酮的不对称直接羟醛缩合反应,对映体过量最高9%.     

酮康唑在玻碳电极上的吸附行为及其测定

报道了一种抗真菌治疗新药酮康唑的吸附行为及其测定。该药物在玻碳电极上预富集后，用示差脉冲伏安法测定，其响应电流与药物浓度在２．０×１０＾－１０－１．０×１０＾－－５ｍｏｌ／Ｌ范围内呈线性关系；检屈限为４．０×１０＾－１１ｍｏｌ／Ｌ。可用于尿和血清样品中药物含量的测定。     

羧基膦－钯－酸体系催化烯烃氢酯基化反应

以钯－膦－酸体系催化烯烃氢酯基化的反应日显重要，而膦配体是决定此反应的重要因素，用二苯基膦乙酸（ＤＰＡ）为配体的钯催化剂体系，对烯烃的氢酯基化反应作了研究。对影响反应的各种因素如反应温度、反应压力、不同的溶剂、膦配体及酸助剂的量等作了考察，发现此配体对烯烃的区域选择性有改善。并用此催化体系对不同结构的烯烃进行了研究，发现有如下的活性顺序：环烯烃＞直链端烯＞直链内烯。     

Optimal Due-Date Determination and Sequencing of <Emphasis Type="Italic">n</Emphasis> Jobs on a Single Machine

Given a set of n jobs with deterministic processing times and the same ready times, the problem is to find the optimal processing-time multiple k* for the T.W.K. due-date assignment method, and the optimal sequence σ* to minimize the total amount of missed due-dates. It is found that k* is a constant for a given job set and σ* should be in S.P.T. sequence. After the theoretical treatment, a numerical example is given for discussion. The optimal results can readily be extended to situations in which the processing times are random variables with known means and having the same coefficient of variation. From a practical point of view, the main merit of this paper is that it demonstrates how, under certain production environments in which completion times of the jobs can be anticipated, to determine the optimal due-dates and obtain the optimal sequence.     

1—苯乙酰基—4—芳酰基氨基硫脲的合成及其在碱催化下的环化反应

1-酰基-4-芳基氨基硫脲类化合物在碱性条件下环化为具有广泛生物活性的3-取代基-4-芳基-1,2,4-三唑啉-5-硫酮的反应报道甚多,但1,4-位都含羰基的酰氨基硫脲在碱性条件下环化反应迄今报道较少。我们曾研究了1-[5-(α-萘)-2H-四唑-2-乙酰基]-4-芳酰基氨基硫脲和1-(α-萘乙酰基)-4-芳酰基氨基硫脲在碱催化下环化为3-取代基-4-芳酰基-1,2,4-三唑啉-5-硫酮的反应,它们在低浓度下均有一定的生物活性。本文研究了1-苯乙酰基-4-芳酰基氨基硫脲1_(a～m)在1mol/L K_2CO_3溶液催化下的环化反应,得到环化产物3-苄基-4-芳酰基-1,2,     

Electronic structure and magnetic properties of TMRh12 clusters

We report an experimental study of energy pooling collisions involving Cs atoms in the 6P and 5D states. The 5D state was populated by a cw dye-laser tuned to the cesium dipole-forbidden transition 6S → 5D at 685.0 nm. The 6P state was populated by subsequent radiative relaxation of the 5D state. The 6P population density was determined from the absorption of a cw diode-laser probe beam. The population densities of the 5D state and the higher, by energy pooling excited states were determined by measuring the corresponding fluorescence intensities relative to the fluorescence intensity from the optically thin quasi-static wings of the cesium D ₂ line. The rate coefficient for the process Cs*(6P)+Cs*(6P)→Cs**(6D)+Cs(6S) is found to be (4.2±0.13)×10^?10 cm³ s^?1 at T=570 K. In addition, estimates of the rate coefficients for the processes Cs*(6P)+Cs*(5D)→Cs**(7D)+Cs(6S) and Cs*(5D)+ Cs*(5D)→Cs**(7F)+Cs(6S) are given.     

等离子体聚合及其聚合物的应用

本文着重综述了烃,含氮、氧的有机化合物,碳氟化合物以及有机硅化合物的等离子体聚合。同时还系统地介绍了等离子体聚合物在制备反渗透膜、分离膜、材料表面的涂层等方面的国内外的最新研究成果。     

Charge transport properties of tris(8-hydroxyquinolinato)aluminum(III): why it is an electron transporter

The charge transport properties of mer-tris(8-hydroxyquinolinato)aluminum(III) (mer-Alq), which is the most widely used electron transport material in OLED, were investigated by quantum chemistry calculations within the framework of the charge hopping model and Marcus electron transfer theory. Internal reorganization energies of 0.276 and 0.242 eV were calculated by the DFT-B3LYP method employing a 6-31 G* basis set for the electrons lambdai(e) and holes lambdai(h), respectively. The relative distances and orientations of Alq molecules in amorphous film were simulated by those in the beta-phase. The intermolecular charge-transfer integrals, Hda(h) and Hda(e), along all 14 hopping pathways were then calculated by the Koopmans Theorem in conjunction with the Hartree-Fock method employing a 6-31 G* basis set as well as by the direct coupling method. The results showed that there were some Hda(e) that were 1 order of magnitude larger than any Hda(h), because hopping pathways with effective overlaps of LUMOs can occur and, thus, large Hda(e). On the other hand, effective overlap of HOMO was absent in all pathways, resulting in a relatively small Hda(h). This difference in the magnitudes of Hda(e) and Hda(h) would predict a 2 orders of magnitude difference in the electron-transfer rate constants and account for the observed 2 orders of magnitude difference in the mobilities of electrons and holes.     

Calculations on the octupolar molecules with enhanced two-photon absorption cross sections based on the Zn (II) and Cu (I) as centers

The equilibrium geometries, electronic structures, as well as one- and two-photon absorption cross sections of a series of octupolar chromophores with Zn(2+) or Cu(+) as coordinate centers and 4,4'-bis(dibutylaminostyryl)-[2,2']-bis(bipyridyl) as ligands have been determined by using B3LYP/6-31G and ZINDO methods. These molecules are designed by controlled combination of two or three bipyridyl ligands with the metal centers. The results show that Zn(2+) is an effective template for the design of octupolar structures which enable it to form tetrahedral and octahedral coordinated complexes; while Cu(+) only exists in a tetrahedral coordinated complex, comparing the tetrahedral complex with Zn(2+) as the center with that of Cu(+) as the center, it is found that the complex with the Cu(+) center is a better two-photon absorption material than the former as far as the transparency/nonlinearity is concerned. Furthermore, for the same metal center of Zn(2+), both one- and two-photon absorptions of the tetrahedral complex are redshifted relative to those of the octahedral complex, is attributed to the spiroconjugation effect in the tetrahedral complex. Our theoretical findings are consistent with recent experimental observations and provide an important foundation for the design of improved transparency-nonlinearity two-photon absorption materials.